Log Parser Studio 2.0 is now available
Since the initial release of Log Parser Studio (LPS) there have been over 30,000 downloads and thousands of customers use the tool on a daily basis. In Exchange support many of our engineers use the tool to solve real world issues every day and in turn share with our customers, empowering them to solve the same issues themselves moving forward. LPS is still an active work in progress; based on both engineer and customer feedback many improvements have been made with multiple features added during the last year. Below is a short list of new features: Improved import/export functionality For those who create their own queries this is a real time-saver. We can now import from multiple XML files simultaneously only choosing the queries we wish to import from multiple query libraries or XML files. Search Query Results The existing feature allowing searching of queries in the library is now context aware meaning if you have a completed query in the query window, the search option searches that query. If you are in the library it searches the library and so on. This allows drilling down into existing query results without having to run a new query if all you want to do is narrow down existing result sets. Input/Output Format Support All LP 2.2 Input and Output formats contain preliminary support in LPS. Each format has its own property window containing all known LP 2.2 settings which can be modified to your liking. Exchange Extensible Logging Support Custom parser support was added for most all Exchange logs. These are covered by the EEL and EELX log formats included in LPS which cover Exchange logs from Exchange 2003 through Exchange 2013. Query Logging I can't tell you how many times myself or another engineer spent lots of time creating the perfect query for a particular issue we were troubleshooting, forgetting to save the query in the heat of the moment and losing all that work. No longer! We now have the capability to log every query that is executed to a text file (Query.log). What makes this so valuable is if you ran it, you can retrieve it. Queries There are now over 170 queries in the library including new sample queries for Exchange 2013. PowerShell Export You can now export any query as a standalone PowerShell script. The only requirement of course is that Log Parser 2.2 is installed on the machine you run it on but LPS is not required. There are some limitations but you can essentially use LPS as a query editor/test bed for PowerShell scripts that run Log Parser queries for you! Query Cancellation The ability to submit a request to cancel a running query has been added which will allow you to cancel a running query in many cases. Keyboard Shortcuts There are now 23 Keyboard shortcuts. Be sure to check these out as they will save you lots of time. To display the short cuts use CTRL+K or Help > Keyboard Shortcuts. There are literally hundreds of improvements and features; far too many to list here so be sure and check out our blog series with existing and upcoming tutorials, deep dives and more. If you are installing LPS for the first time you'll surely want to review the getting started series: Getting started with Log Parser Studio Getting started with Log Parser Studio, part 2 Getting started with Log Parser Studio, part 3 If you are already familiar with LPS and are installing this latest version, you'll want to check out the upgrade blog post here: Log Parser Studio: upgrading from v1 to v2 Additional LPS articles can be found here: http://blogs.technet.com/b/karywa/ LPS doesn't require an install so just extract to the folder of your choice and run LPS.EXE. If you have the previous version of LPS and you have added your own custom queries to the library, be sure to export those queries as a backup before running the newest version. See the "Upgrading to LPS V2" blog post above when upgrading. Kary WallOutlook Connectivity with MAPI over HTTP
Among the many new features delivered in Exchange 2013 SP1 is a new method of connectivity to Outlook we refer to as MAPI over HTTP (or MAPI/HTTP for short). We’ve seen a lot of interest about this new connection method and today we’ll give you a full explanation of what it is, what it provides, where it will take us in the future, and finally some tips of how and where to get started enabling this for your users. What is MAPI over HTTP? MAPI over HTTP is a new transport used to connect Outlook and Exchange. MAPI/HTTP was first delivered with Exchange 2013 SP1 and Outlook 2013 SP1 and begins gradually rolling out in Office 365 in May. It is the long term replacement for RPC over HTTP connectivity (commonly referred to as Outlook Anywhere). MAPI/HTTP removes the complexity of Outlook Anywhere’s dependency on the legacy RPC technology. Let’s compare the architectures. MAPI/HTTP moves connectivity to a true HTTP request/response pattern and no longer requires two long-lived TCP connections to be open for each session between Outlook and Exchange. Gone are the twin RPC_DATA_IN and RPC_DATA_OUT connections required in the past for each RPC/HTTP session. This change will reduce the number of concurrent TCP connections established between the client and server. MAPI/HTTP will generate a maximum of 2 current connections generating one long lived connection and an additional on-demand short-lived connection. Outlook Anywhere also essentially double wrapped all of the communications with Exchange adding to the complexity. MAPI/HTTP removes the RPC encapsulation within HTTP packets sent across the network making MAPI/HTTP a more well understood and predictable HTTP payload. An additional network level change is that MAPI/HTTP decouples the client/server session from the underlying network connection. With Outlook Anywhere connectivity, if a network connection was lost between client and server, the session was invalidated and had to be reestablished all over again, which is a time-consuming and expensive operation. In MAPI/HTTP when a network connection is lost the session itself is not reset for 15 minutes and the client can simply reconnect and continue where it left off before the network level interruption took place. This is extremely helpful for users who might be connecting from low quality networks. Additionally in the past, an unexpected server-side network blip would result in all client sessions being invalidated and a surge of reconnections being made to a mailbox server. Depending on the number of Outlook clients reconnecting, the re-establishing of so many RPC/HTTP connections might strain the resources of the mailbox server, and possibly extend the outage in scope (to Outlook clients connected to multiple servers) and time, caused by a single server-side network blip. Why MAPI over HTTP? You are probably asking yourself why the Exchange team would create a complete replacement for something so well-known and used. Let us explain. The original Outlook Anywhere architecture wasn’t designed for today’s reality of clients connecting from a wide variety of network types – many of these are not as fast or reliable as what was originally expected when Outlook Anywhere was designed. Consider connections from cellular networks, home networks, or in-flight wireless networks as a few examples. The team determined the best way to meet current connection needs and also put Exchange in the position to innovate more quickly was to start with a new simplified architecture. The primary goal of MAPI/HTTP is provide a better user experience across all types of connections by providing faster connection times to Exchange – yes, getting email to users faster. Additionally MAPI/HTTP will improve the connection resiliency when the network drops packets in transit. Let’s quantify a few of these improvements your users can expect. These results represent what we have seen in our own internal Microsoft user testing. When starting Outlook users often see the message “Connecting to Outlook” in the Outlook Status bar. MAPI/HTTP can reduce the amount of time a user waits for this connection. In the scenario when a user first launches Outlook the time to start synchronization improved to 30 seconds vs. 90 seconds for Outlook Anywhere for 70% of the monitored clients. Improvements are also delivered when clients are resuming from hibernation or simply re-connecting to a new network. Testing showed that 80% of the clients using MAPI/HTTP started syncing in less than 30 seconds vs. over 40 seconds for Outlook Anywhere clients when resuming from hibernation. This improvement was made possible as MAPI/HTTP implements a pause/resume feature enabling clients to resume using an existing connection rather than negotiating a new connection each time. Current sessions for MAPI/HTTP are valid for 15 minutes, but as we fine tune and expand this duration, these improvements will be even more noticeable. Improvements aren’t limited to end users. IT administrators will gain greater protocol visibility allowing them to identify and remediate situations faster and with more confidence. Due to MAPI/HTTP moving to a more traditional HTTP protocol payload, the ability to utilize already known tools common to HTTP debugging is a reality. IIS and HttpProxy logs will now contain information similar to other HTTP based protocols like Outlook Web App and be able to pass information via headers. At times in the past, certain debug procedures for RPC/HTTP were only available via proprietary internal Microsoft tools. This move should put all customers on the same level playing field as far as what tools are available for debug purposes. Exchange administrators also will find response returned by Autodiscover for MAPI/HTTP to Outlook is greatly simplified. The settings returned are just protocol version and endpoint URLs for Outlook to connect to Exchange mailbox and directory fr om inside or outside the customer’s corporate network. Outlook treats the URLs returned as opaque and uses as-is, minimizing the risk of connectivity breaking with future endpoint changes. Since MAPI/HTTP, like any other web protocol, simply sends an anonymous HTTP request to Exchange and gets back the authentication settings, there is no need for Autodiscover to advertise the authentication settings. This makes it easier to roll out changes in authentication settings for Outlook. The future MAPI/HTTP puts the Exchange team in position to innovate more quickly. It simplifies the architecture removing dependency on the RPC technologies which are no longer evolving as quickly as the customers demand. It provides the path for extensibility of the connection capabilities. A new capability that is on the roadmap for Outlook is to enable multi-factor authentication for users in Office 365. This capability is made possible with the use of MAPI/HTTP and is targeted to be delivered later this year. For a deeper look at this upcoming feature you can review the recent Multi-Factor Authentication for Office 365 blog post. This won’t stop with Office 365 MFA, but provides the extensibility foundation for 3 rd party identity providers. How does MAPI/HTTP work? Let’s walk through the scenario of an Outlook 2013 SP1 client connecting to Exchange Server 2013 SP1 after MAPI/HTTP has been enabled. The Outlook client begins with an Autodiscover POST request. In this request Outlook includes a new attribute that advertises the client is MAPI/HTTP capable with the attribute X-MapiHTTPCapability = 1. The Exchange server sees the request is coming from a MAPI/HTTP capable client and responds with the MAPI/HTTP information including the settings on how to connect to the mailbox using MAPI/HTTP. This assumes the MAPI/HTTP has been configured and enabled on the server. The Outlook client detects the new connection path and prompts the user to restart Outlook to switch to use the new connection. While the restart is pending Outlook will continue using Outlook Anywhere. We recommend you deploy the latest Office client updates to provide the best user experience. The updates remove the prompt and clients are allowed to make the transition at the next unprompted restart of Outlook. After the restart, Outlook now uses MAPI/HTTP to communicate with Exchange. What’s required? So now we have a clear set of advantages you can offer users, let’s review the requirements to enable MAPI/HTTP. Server Requirements: Use of MAPI/HTTP requires all Exchange 2013 Client Access Servers to be updated to Exchange Server 2013 SP1 (or later). The feature is disabled by default in SP1 so you can get the servers updated without anyone noticing any changes. If you are an Office 365 Exchange Online customer you won’t have anything to worry about on the service side of deployment. Client Requirements: Outlook clients must be updated to use MAPI/HTTP. Office 2013 SP1 or Office 365 ProPlus February update (SP1 equivalent for ProPlus) are required for MAPI/HTTP. It is recommend you deploy the May Office 2013 public update or the April update for Office 365 ProPlus to eliminate the restart prompt when MAPI/HTTP is enabled for users. Outlook 2010 was updated to support MAPI/HTTP in the January 2015 Public Update, and additional fixes for it were released in the April 2015 Public Update. Prior version clients will continue to work as-is using Outlook Anywhere. Outlook Anywhere is the supported connection method for those clients. We will not be backporting MAPI/HTTP to Outlook 2007 or earlier versions. How to get ready Part one of getting ready is to get the required updates to your servers and clients as described in the prior section. Part two of getting ready is evaluating potential impacts MAPI/HTTP might have on your on-premises servers. Again if you an Office 365 customer you can ignore this bit. When you implement MAPI/HTTP in your organization, it will have an impact on your Exchange server resources. Before you go any further you need to review the impacts to your server resources. The Exchange 2013 Server Role Requirements Calculatorhas been updated to factor in use of MAPI/HTTP. You need to use the most recent version of the calculator (v6.3 or later) before you proceed. MAPI/HTTP increases the CPU load in the Exchange Client Access Servers. This is a 50% increase over Exchange 2013 RTM, however it is still lower than Exchange 2010 requirements. As you plan be mindful that deploying in a multi-role configuration will minimize the impact to your sizing. Again use the calculator to review potential impacts this may have in your environment. This higher CPU use is due to the higher request rate with several short-lived connections, with each request taking care of authentication and proxying. To provide the best MAPI/HTTP performance you need to install .NET 4.5.1 on your Exchange 2013 servers. Installing .NET 4.5.1 will avoid long wait times for users thanks to a fix to ensure the notification channel remains asynchronous to avoid queued requests. The change in communication between Exchange and Outlook has a small impact on the bytes sent over the wire. The header content in MAPI/HTTP is responsible for an increase in bytes transferred. In a typical message communications we have observed an average packet size increase of 1.2% versus Outlook Anywhere for a 50 KB average packet. In scenarios of data transfers over 10 MB the increase in bytes over the wire is 5-10%. These increases assumes an ideal network where connections are not dropped or resumed. If you consider real world conditions you may actually find MAPI/HTTP data on the wire may be lower than Outlook Anywhere. Outlook Anywhere lacks the ability to resume connections and the cost of re-syncing items can quickly outweigh the increase from the MAPI/HTTP header information. Now deploy MAPI/HTTP Now that you have prepared your servers with SP1, updated your clients, and reviewed potential sizing impacts you are ready to get on with implementing MAPI/HTTP. It is disabled by default in SP1 and you must take explicit actions to configure and enable it. These steps are well covered in the MAPI over HTTPTechNet article. A few important things to remember in your deployment. Namespace: MAPI/HTTP is a new endpoint on CAS and can utilize both an internal namespace and an external namespace. For more information on how to properly plan your namespace design, see Namespace Planning in Exchange 2013 and Load Balancing in Exchange 2013. Certificates: The certificate used in Exchange will need to include both the internal and external MAPI/HTTP virtual directories to avoid any user certificate prompts, thus consider if the names exist on your certificates. Refer to the certificate planning post for additional help planning. MAPI/HTTP Configuration: Enabling MAPI/HTTP is an organizational configuration in Exchange, you won’t have the ability configure this for a subset of servers. If you require more specific control you can control the client behavior with a registry key. NOTE: If you require more specific control you can control the client behavior with a registry key on each client machine. This is not recommended or required but included if your situation demands this level of control. This registry entry prevents Outlook from sending the MAPI/HTTP capable flag to Exchange in the Autodiscover request. When you change the registry key on a client it will not take effect until the next time the client performs an Autodiscover query against Exchange. To disallow MAPI/HTTP and force RPC/HTTP to be used. HKEY_CURRENT_USER\Software\Microsoft\Exchange] “MapiHttpDisabled”=dword:00000001 To allow MAPI/HTTP simply delete the MapiHttpDisabled DWORD, or set it to a value of 0 as below. HKEY_CURRENT_USER\Software\Microsoft\Exchange] “MapiHttpDisabled”=dword:00000000 Connectivity: An important final consideration is to verify load balancers, reverse proxies, and firewalls are configured to allow access to the MAPI/HTTP virtual directories. At this time ForeFront Unified Access Gateway (UAG) 2010 SP4 is not compatible with MAPI/HTTP. The UAG team has committed to deliver support for MAPI/HTTP in a future update. How do I know it is working? There are a few quick ways to verify your configuration is working as expected. 1. Test with the Test-OutlookConnectivity cmdlet Use this command to test MAPI/HTTP connectivity: Test-OutlookConnectivity -RunFromServerId Contoso -ProbeIdentity OutlookMapiHttpSelfTestProbe This test is detailed in the MAPI over HTTPTechNet Article. 2. Inspect MAPI/HTTP server logs Administrators can review the following MAPI/HTTP log files to validate how the configuration is operating: Location Path CAS: %ExchangeInstallPath%Logging\HttpProxy\Mapi\HTTP Mailbox: %ExchangeInstallPath%Logging\MAPI Client Access\ Mailbox: %ExchangeInstallPath%Logging\MAPI Address Book Service\ 3. Check Outlook connection status on clients You can also quickly verify that the client is connected using MAPI/HTTP. The Outlook Connection status dialog can be launch by CTRL-right clicking the Outlook icon in the notification area and selecting Connection Status. Here are the few key fields to quickly confirm the connection is using MAPI/HTTP. Field Value Protocol HTTP (v/s RPC/HTTP for Outlook Anywhere) Proxy Server Empty Server name Actual server name (v/s GUID for Outlook Anywhere connections) Summary MAPI/HTTP provides a simplified transport and resulting architecture for Outlook to connect with Exchange. It enables improved user experiences to allow them faster access to mail and improves the resilience of their Outlook connections. These investments are the foundation for future capabilities such as multi-factor authentication in Outlook. It also helps IT support and troubleshoot client connection issues using standard HTTP protocol tools. As with all things new you must properly plan your implementation. Use the deployment guidanceavailable on TechNet and the updated sizing recommendations in the calculator before you start your deployment. With proper use it will guide you to a smooth deployment of MAPI/HTTP. Special thanks to Brian Day and Abdel Bahgat for extensive contributions to this blog post. Brian Shiers | Technical Product Manager MAPI/HTTP FAQ We collected a number of questions which frequently came up during the development, internal dogfooding, and customer TAPtesting of MAPI/HTTP. We hope these answer most of the questions you may have about MAPI/HTTP. Can MAPI/HTTP be enabled/disabled on a per-server basis? No, it is an organization-wide Exchange setting. The user experience mentioned during database failovers when one server is not yet MAPI/HTTP capable made the functionality to turn MAPI/HTTP on and off per server not a viable solution. Can MAPI/HTTP be enabled/disabled on a per-mailbox basis? No, there is not currently a Set-CasMailbox parameter to enable/disable MAPI/HTTP for a single mailbox. I updated the registry key to disable MAPI/HTTP on a client but the connection didn’t change? The registry entry simply controls what Outlook sends to Exchange about its MAPI/HTTP capability during an Autodiscover request. It does not immediately change the connection method Outlook is using nor will it change it with a simple restart of Outlook. Remember, the Autodiscover response Outlook gets only has MAPI/HTTP or RPC/HTTP settings in it so it has no way to immediately switch types. You must allow Outlook to perform its next Autodiscover request and get a response from Exchange after setting this registry entry before the change will take place. If you must attempt to speed along this process, there are two options. Set the registry entry as you wish, close Outlook, delete the Outlook profile, and then restart Outlook and go through the profile wizard. This should result in an immediate switch, but any settings stored in the Outlook profile are lost. Set the registry entry as you wish, close Outlook, delete the hidden Autodiscover response XML files in %LOCALAPPDATA%\Microsoft\Outlook, and restart Outlook. Restart Outlook once more to complete the switch. What happens if a user’s mailbox database is mounted on a MAPI/HTTP capable server and then a database failover happens to a non-MAPI/HTTP capable server? E.g. When not all mailbox servers in a DAG are MAPI/HTTP capable and MAPI/HTTP has already been enabled in the organization, and then a mailbox failover takes place between the SP1 (or later) and pre-SP1 servers. Additionally this could happen if you move a mailbox from a MAPI/HTTP capable mailbox server to a server that is not MAPI/HTTP capable. In the above example Outlook would fail to connect and when Autodiscover next ran the user would get an Outlook restart notification warning because MAPI/HTTP is no longer a viable connection method due to the mailbox being mounted on a pre-SP1 server. After the client restart the client profile would be back to utilizing RPC/HTTP. Note: While a mix of MAPI/HTTP capable and non-capable mailbox Exchange servers in the same DAG are supported in an environment with MAPI/HTTP enabled, it is very strongly not recommended due to the possible user experience outlined above. It is suggested the entire organization be upgraded to SP1 or later before enabling MAPI/HTTP in the organization. What if a user accesses additional mailboxes where MAPI/HTTP is not yet available? Outlook profiles can continue access additional resources using non-MAPI/HTTP connectivity methods even if the user’s primary mailbox utilizes MAPI/HTTP. For example a user can continue to access Legacy Public Folders or Shared Mailboxes on other Exchange servers not utilizing MAPI/HTTP. During the Autodiscover process Exchange will determine and hand back to Outlook the proper connectivity method necessary for each resource being accessed. If MAPI/HTTP becomes unreachable will a client fallback to RPC/HTTP? No, a user’s profile will never attempt to use RPC/HTTP if MAPI/HTTP becomes unavailable because the original Autodiscover response only contained one connection method to use. There is no fallback from MAPI/HTTP to RPC/HTTP or vice versa. Normal high availability design considerations should ensure the MAPI/HTTP endpoint remain accessible in the event of server or service failures. Is MAPI/HTTP replacing Exchange Web Services (EWS)? No, MAPI/HTTP is not a replacement for EWS and there are no plans to move current EWS clients to MAPI/HTTP. Is RPC/HTTP being deprecated as an available connection method? Over time this may take place as non-MAPI/HTTP capable Outlook versions age out of their product support lifecycle, but there are no immediate plans to remove RPC/HTTP as a valid connection method. What authentication methods does MAPI/HTTP support? A huge architectural improvement by moving to MAPI/HTTP is that MAPI/HTTP is abstracted from authentication. In short authentication is done at the HTTP layer, so whatever HTTP can do, MAPI/HTTP can use. Does moving the MAPI/HTTP negatively affect the Lync client at all? No, the Lync client uses the same profile as configured by Outlook and will connect via whatever connectivity method is in use by Outlook. Is there any kind of SDK/API for third party application usage of MAPI/HTTP? The MAPI/HTTP protocol is publically documented (PDF download) and has the same level of documentation support as RPC/HTTP. There are no plans to update the MAPI CDO library for MAPI/HTTP and third party companies are still encouraged to utilize Exchange Web Services as the long-term protocol for interaction with Exchange as discussed in Exchange 2013 Client Access Server Rolearticle. What are the client requirements for MAPI/HTTP? Use of MAPI/HTTP requires Outlook 2013 clients to obtain Office 2013 Service Pack 1 or the February update for Office 365 ProPlus clients. Outlook 2010 was updated to support MAPI/HTTP in the January 2015 Public Update, and additional fixes for it were released in the April 2015 Public Update. How does this affect publishing Exchange 2013 via ARR, WAP, TMG, UAG, B2M, ABC, BBD … Publishing Exchange 2013 with MAPI/HTTP in use does not change very much. You will need to ensure devices in front of Exchange handling user access to CAS are allowing access to the Default Web Site’s /mapi/ virtual directory. At this time UAG SP3 is not compatible with MAPI/HTTP even with all filtering options disabled. UAG plans to add support for MAPI/HTTP in a future update. Learn More Still want more information? Review the following sessions on this topic from Microsoft Exchange Conference 2014 Outlook Connectivity: Current and FutureOutlook Connectivity: Current and FutureOutlook Connectivity: Current and Future What's New in Outlook 2013 and Beyond What's New in Authentication for Outlook 2013GAL Photos in Exchange 2010 and Outlook 2010
Over the years, displaying recipient photographs in the Global Address List (GAL) has been a frequently-requested feature, high on the wish lists of many Exchange folks. Particularly in large organizations or geographically dispersed teams, it's great to be able to put a face to a name for people you've never met or don't frequently have face time with. Employees are commonly photographed when issuing badges/IDs, and many organizations publish the photos on intranets. There have been questions about workarounds or third-party add-ins for Outlook, and you can also find some sample code on MSDN and elsewhere. A few years ago, an unnamed IT person wrote ASP code to make employee photos show up on the intranet based on the Employee ID attribute in Active Directory - which was imported from the company's LDAP directory. A fun project to satisfy the coder alter-ego of the said IT person. Luckily, you won't need to turn to your alter-ego to do this. Exchange 2010 and Outlook 2010 make this task a snap, with help from Active Directory. Active Directory includes the Picture attribute (we'll refer to it using its ldapDisplayName: thumbnailPhoto) to store thumbnail photos, and you can easily import photos— not the high-res ones from your 20 megapixel digital camera, but small, less-than-10K-ish ones, using Exchange 2010's Import-RecipientDataProperty cmdlet. Photos in Active Directory? Really? The first question most IT folks would want to ask is— What's importing all those photos going to do to the size of my Active Directory database? And how much Active Directory replication traffic will this generate? The thumbnailPhoto attribute can accomodate photos of up to 100K in size, but the Import-RecipientDataProperty cmdlet won't allow you to import a photo that's larger than 10K. (Note, the attribute limit was stated as 10K earlier. This has been updated to state the correct value. -Bharat) The original picture used in this example was 9K, and you can compress it further to a much smaller size - let's say approximately 2K-2.5K, without any noticeable degradation when displayed at the smaller sizes. If you store user certificates in Active Directory, the 10K or smaller size thumbnail pictures are comparable in size. Storing thumbnails for 10,000 users would take close to 100 Mb, and it's data that doesn't change frequently. Note: The recommended thumbnail photo size in pixels is 96x96 pixels. With that out of the way, let's go through the process of adding pictures. A minor schema change First stop, the Active Directory Schema. A minor schema modification is required to flip the thumbnailPhoto attribute to make it replicate to the Global Catalog. Note: If you're on Exchange 2010 SP1, skip this step. The attribute is modified by setup / SchemaPrep. If you haven't registered the Schema MMC snap-in on the server you want to make this change on, go ahead and do so using the following command: Regsvr32 schmmgmt.dll Fire up a MMC console (Start -> Run -> MMC) and add the Schema snap-in In the Active Directory Schema snap-in, expand the Attributes node, and then locate the thumbnailPhoto attribute. (The Schema snap-in lists attributes by its ldapDisplayName). In the Properties page, select Replicate this attribute to the Global Catalog, and click OK. Figure 1: Modifying the thumbnailPhoto attribute to replicate it to Global Catalog Loading pictures into Active Directory Now you can start uploading pictures to Active Directory using the Import-RecipientDataProperty cmdlet, as shown in this example: Import-RecipientDataProperty -Identity "Bharat Suneja" -Picture -FileData ([Byte[]]$(Get-Content -Path "C:\pictures\BharatSuneja.jpg" -Encoding Byte -ReadCount 0)) To perform a bulk operation you can use the Get-Mailbox cmdlet with your choice of filter (or use the Get-DistributionGroupMember cmdlet if you want to do this for members of a distribution group), and pipe the mailboxes to a foreach loop. You can also retrieve the user name and path to the thumbnail picture from a CSV/TXT file. Thumbnails in Outlook 2010 Now, let's fire up Outlook 2010 and take a look what that looks like. In the Address Book/GAL properties for the recipient Figure 2: Thumbnail displayed in a recipient's property pages in the GAL When you receive a message from a user who has the thumbnail populated, it shows up in the message preview. Figure 3: Thumbnail displayed in a message While composing a message, the thumbnail also shows up when you hover the mouse on the recipient's name. Figure 4: Recipient's thumbnail displayed on mouse over when composing a message There are other locations in Outlook where photos are displayed. For example, in the Account Settings section in the Backstage Help view. Update from the Outlook team Our friends from the Outlook team have requested us to point out that the new Outlook Social Connector also displays GAL Photos, as well as photos from Contacts folders and from social networks, as shown in this screenshot. Figure 5: Thumbnail photos displayed in the People Pane in the Outlook Social Connector More details and video in Announcing the Outlook Social Connector on the Outlook team blog. GAL Photos and the Offline Address Book After you've loaded photos in Active Directory, you'll need to update the Offline Address Book (OAB) for Outlook cached mode clients. This example updates the Default Offline Address Book: Update-OfflineAddressBook "Default Offline Address Book" In Exchange 2010, the recipient attributes included in an OAB are specified in the ConfiguredAttributes property of the OAB. ConfiguredAttributes is populated with a default set of attributes. You can modify it using the Set-OfflineAddressBook cmdlet to add/remove attributes as required. By default, thumbnailPhoto is included in the OAB as an Indicator attribute. This means the value of the attribute isn't copied to the OAB— instead, it simply indicates the client should get the value from Active Directory. If an Outlook client (including Outlook Anywhere clients connected to Exchange using HTTPS) can access Active Directory, the thumbnail will be downloaded and displayed. When offline, no thumbnail downloads. Another example of an Indicator attribute is the UmSpokenName. You can list all attributes included in the default OAB using the following command: (Get-OfflineAddressBook "Default Offline Address Book").ConfiguredAttributes For true offline use, you could modify the ConfiguredAttributes of an OAB to make thumbnailPhoto a Value attribute. After this is done and the OAB updated, the photos are added to the OAB (yes, all 20,000 photos you just uploaded...). Depending on the number of users and sizes of thumbnail photos uploaded, this would add significant bulk to the OAB. Test this scenario thoroughly in a lab environment— chances are you may not want to provide the GAL photo bliss to offline clients in this manner. To prevent Outlook cached mode clients from displaying thumbnail photos (remember, the photo is not in the OAB – just a pointer to go fetch it from Active Directory), you can remove the thumbnailPhoto attribute from the ConfiguredAttributes property of an OAB using the following command: $attributes = (Get-OfflineAddressBook "Default Offline Address Book").ConfiguredAttributes $attributes.Remove("thumbnailphoto,Indicator") Set-OfflineAddressBook "Default Offline Address Book" -ConfiguredAttributes $attributes Bharat Suneja Updates: 11/3/2010: Corrected size limit of thumbnailPhoto attribute to 100K. 8/25/2011: Added note to reflect Exchange 2010 SP1 setup / SchemaPrep modifies thumbnailPhoto attribute to replicate to Global Catalog. GAL Photos now has an FAQ. Check out GAL Photos: Frequently Asked Questions. To visit this post again, use the short URL aka.ms/galphotos. To go to the 'GAL Photos: Frequently Asked Questions' post, use aka.ms/galphotosfaq.Controlling Exchange ActiveSync device access using the Allow/Block/Quarantine list
Note: Customers looking for more device access or management control in Microsoft 365, should explore Basic Mobility and Security or Microsoft Intune. What is the Allow/Block/Quarantine list? In Exchange 2010 we added a feature called the Allow/Block/Quarantine list (or ABQ for short). This feature was designed to help IT organizations control which of the growing number of Exchange ActiveSync-enabled devices are allowed to connect to their Exchange Servers. With this feature, organizations can choose which devices (or families of devices) can connect using Exchange ActiveSync (and conversely, which are blocked or quarantined). Some of you may remember my previous post on this topic dealing with organizations that do not have Exchange 2010 and thus I wanted to show you the far better way you can do this in Exchange 2010 (which is also what you will see in Office 365 and Exchange Online if you are looking at our cloud-based offerings). It is important to understand that the ABQ list is not meant to displace policy controls implemented using Exchange ActiveSync policies. Policy controls allow you to control and manage device features (such as remote wipe, PIN passwords, encryption, camera blocking, etc.) whereas the ABQ list is about controlling which devices are allowed to connect (for example, there may be a lot of devices that support EAS PIN policies, but some IT departments only want to allow certain devices to connect to limit support or testing costs). The easy takeaway is that Exchange ActiveSync policies allow you to limit device access by capabilities while the Allow/Block/Quarantine list allows you to control device access by device type. If you're curious as to what devices OS support which policies, the Wikipedia article we blogged about is a good place to look. Different device access models for different folks When we designed the ABQ list, we talked to a lot of organizations to find out how all of you use (or wanted to use) this kind of technology. What we realized is that there is a continuum of organizations; from permissive organizations that let employees connect whatever device they have to their Exchange Server, all the way to restrictive organizations that only support specific devices. Since we always want to make our software as flexible for IT as possible (as we know there are a lot of you folks that are using our software in a lot of different ways) we created this feature so that no matter which type of organization you are (or even if you are one that is in between these two extremes) we could help meet your needs. Below are some descriptions and "how-to"s for using the ABQ list in these different ways. The restrictive organization Restrictive organizations follow a more traditional design where only a set of supported devices is allowed to connect to the Exchange server. In this case, the IT department will only choose to allow the particular devices they support and all other devices are blocked. It's important to note that a restrictive organization is created by specifying a set of allowed devices and blocking the unknown. The permissive organization: Permissive organizations allow all (or most) to connect to their Exchange Server. In these cases, the ABQ list can help organizations block a particular device or set of devices from connecting. This is useful if there's a security vulnerability or if the device is putting a particularly heavy load on the Exchange server. In these cases, the IT department can identify the misbehaving device and block that device until a fix or update for that device brings it into compliance. All other devices, including the unknown devices, are given access. The one off case: Of course, if you are limiting the devices that connect to your organization, there's almost always a need for an exception. Whether it's testing a new device before rolling it out to the organization as a supported device, or an exception made for an executive, we wanted to give you the ability to make an exception without allowing all users with that device to access your organization's email and PIM data. When to quarantine: Quarantining devices is useful when an IT department wants to monitor new devices connecting to their organization. Both permissive and restrictive organizations may choose to employ this mechanism. In a permissive organization, quarantine can be used so that IT administrators know what devices, and which users, are making new connections. In restrictive organizations, this can be used to see who is trying to work around policy and also gauge demand from "Bring Your Own Device" (BYOD) users. Now that we've gone through the theory, let's talk about how we would do this in practice. Accessing the ABQ settings: Log in to the Exchange Control Panel (ECP) (you can also access the ECP from Outlook Web App (OWA) by selecting Options > See all options) In the ECP , make sure you are managing My Organization (#1 in the screenshot below). Be aware that most users won't see the "My Organization" option — it's only visible to users with Exchange Administrator access. Select Phone & Voice (#2 in the screenshot below) > ActiveSync Access tab (#3 in the screenshot below). This is the Allow/Block/Quarantine configuration screen. Note for all you Exchange Management Shell (EMS) gurus, you can also configure device access using PowerShell cmdlets if you prefer. Creating a device (or a family of devices) rule: To create a new rule, select New from the Device Access Rules section of the ABQ page (#5 in the screenshot above). When setting up a rule for a device, it is important to understand the difference between the "family" of the device and the specific device. This information is communicated as part of the EAS protocol and is reported by the device itself. In general, you can think of the deivce rule as applying only to the particular device type (like an HTC-ST7377 as shown in the image below) whereas a device family might be something more broad like "Pocket PC". This distinction between the specific (device type) and the general (device family) is important since many device manufacturers actually release the same device with different names on different carriers. To make it so that you don't have to make a separate rule for each device. For instance, the HTC Touch Pro was available on all four majour US carriers as well as some of the regional ones, and that's just the USA, not to mention the other versions around the world. As you can see, making a rule for each of those different devices (which are all in the same family and effectively the same device) could mean a lot of extra work for IT, so we added the family grouping to help you make good decisions about devices in bulk. It's important to note that when making a new rule you select the device family or the model but not both. Once you've selected the device or a device family, you can then choose what Exchange will do with that device (in this example, I'm just going to do a specific device). This brings you to the New Device Access Rule page. The easiest way to set the rule is to select Browse, which will show you a list of all the devices or device families that have recently connected to your Exchange Server. Once you've selected the device or family, you can choose the action to take. This is where you can choose to block the device if you are a permissive organization looking to limit a specific device for a specific reason or where you can set access rules if you are a restrictive organization (in such a case you would just create an allow rule for each supported device and then set the state for all unknown devices to block (we'll talk about how to set the action for unknown devices in the next section)). Once you select the action (Allow access, Block access, or Quarantine), click Save and you're done! You can repeat this process for each rule you want to create. You can also have both block and allow rules simultaneously. Setting up a rule for unknown devices: To access the rule for unknown devices, select Edit (#4 in Figure 5 above). On the Exchange ActiveSync Settings page, you can configure the action to take when Exchange sees a user trying to connect with a device that it does not recognize. By default, Exchange allows connections from all devices for users that are enabled for EAS . This example configures the Exchange organization to quarantine all unknown devices. This means that if there's no rule for the device (or device family) or if there's no exception for the particular user, then an unknown device will follow this behavior. Quarantine notifications We have the ability to specify who gets an email alert when a device is placed in quarantine. You can add one or more administrators (or users) or even a distribution group to this list of notified individuals. Anyone on this list will receive an email like the one shown in the screenshot below. The notification provides you information about who tried to connect the device, the device details and when the attempt was made. Custom quarantine message You can also set a custom message that will be delivered to the user in their Inbox and on their device. Although the device is in quarantine, we send this one message to the device so the user doesn't automatically call help desk because their device isn't syncing. The custom message is added to the notification email to the user that their device is in quarantine. The user and device will also now appear on the Quarantined Devices list on the ABQ configuration page. Managing Quarantined Devices The device will stay in quarantine until an administrator decides to allow or block the device in quarantine. This can be done by selecting the device and then clicking on the Allow or Block buttons in Quarantined Devices. This creates a personal exemption (the "one off case" mentioned earlier). If you wish to create an access rule that is to apply to all devices of the same family or model, you can select Create a rule for similar devices to open a new, prepopulated, rule. Making changes: Of course we realize that many organizations are dynamic and have changing requirements and policies. Any of the rules that have been set up can be changed dynamically by accessing the ABQ page in the ECP and editing, deleting, or adding the desired rule. Adam Glick (@MobileGlick) Sr. Technical Product Manager P.S. To read about Microsoft's licensing of Exchange ActiveSync, check out this article on Microsoft NewsCenter. Julia White also put up a more business focused blog in the UC Blog about the importance of EAS to Exchange 2010 customers.Client Connectivity in an Exchange 2016 Coexistence Environment with Exchange 2010
Our goal with this article is to articulate the various client connectivity scenarios you may encounter in your Exchange 2016 designs. To that end, this article will begin with a walk through of a deployment that consists of Exchange 2010 in a multi-site architecture and show how the connectivity changes with the introduction of Exchange 2016. Existing Environment As you can see from the above diagram, this environment contains three Active Directory sites: Internet Facing AD Site (Site1) - This is the main AD site in the environment and has exposure to the Internet. This site has Exchange 2010 servers. There are two namespaces associated with this location – mail.contoso.com and autodiscover.contoso.com resolve to the CAS2010 infrastructure. Regional Internet Facing AD Site (Site2) - This is an AD site that has exposure to the Internet. This site has Exchange 2010 servers. The primary namespace is mail-region.contoso.com and resolves to the CAS2010 infrastructure located within this AD site. Non-Internet Facing AD Site (Site3) - This is an AD site that does not have exposure to the Internet. This site contains Exchange 2010 infrastructure. Note: The term, Internet Facing AD Site, simply means any Active Directory site containing Exchange servers whose virtual directories have the ExternalURL property populated. Similarly, the term, Non-Internet Facing AD Site, simply means any Active Directory site containing Exchange servers whose virtual directories do not have ExternalURL property populated. To understand the client connectivity before we instantiate Exchange 2016 into the environment, let’s look at how each protocol works for each of the three users. Autodiscover The Autodiscover namespace, autodiscover.contoso.com, as well as, the internal SCP records resolve to the CAS2010 infrastructure located in Site1. Outlook clients and ActiveSync clients (on initial configuration) will submit Autodiscover requests to the CAS2010 infrastructure and retrieve configuration settings based on their mailbox’s location. Note: The recommended practice is to configure the 2010 Client Access server’s AutoDiscoverServiceInternalUri value (which is the property value you use to set the SCP record) to point to autodiscover.contoso.com, assuming split-brain DNS is in place. If split-brain DNS is not configured, then set AutoDiscoverServiceInternalUri to a value that resolves to the load balanced VIP for the 2010 Client Access servers in your environment. For more information on how Autodiscover requests are performed, see the whitepaper, Understanding the Exchange 2010 Autodiscover Service. Internal Outlook Connectivity For internal Outlook clients using RPC/TCP connectivity whose mailboxes exist on Exchange 2010, they will connect to the Exchange 2010 RPC Client Access array endpoint (assuming one exists). Keep in mind the importance of configuring the RPC Client Access array endpoint correctly, as documented in Ambiguous URLs and their effect on Exchange 2010 to Exchange 2013 Migrations. Outlook Anywhere Red User will connect to mail.contoso.com as his RPC proxy endpoint. CAS2010 in Site1 will de-encapsulate the RPC data embedded within the HTTP packet and since the target mailbox database is located within the local site, will retrieve the necessary data from the local Exchange 2010 Mailbox server. Blue User will connect to mail.contoso.com as his RPC proxy endpoint. CAS2010 in Site1 will de-encapsulate the RPC data embedded within the HTTP packet, determine that the mailbox server hosting the mailbox is located in another AD site (in this case Site3) and proxy the Outlook RPC data to the target Exchange 2010 Client Access server. Orange User will connect to mail-region.contoso.com as his RPC proxy endpoint. CAS2010 in Site2 will de-encapsulate the RPC data embedded within the HTTP packet and since the target mailbox database is located within the local site, will retrieve the necessary data from the local Exchange 2010 Mailbox server. Note: In addition to the mail and directory connections, Outlook Anywhere clients also utilize Exchange Web Services and an Offline Address Book, url’s for which are provided via the Autodiscover response. Outlook Web App For more information, see the article Upgrading Outlook Web App to Exchange 2010. Red User will connect to mail.contoso.com as his namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, determine that the mailbox is located within the local AD site and retrieve the necessary data from the Exchange 2010 Mailbox server. Blue User will connect to mail.contoso.com as his namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site3, which does not contain any OWA ExternalURLs. CAS2010 in Site1 will proxy the request to CAS2010 in Site3. CAS2010 in Site3 will retrieve the necessary data from the Exchange 2010 Mailbox server. For the Orange User, there are three possible scenarios depending on what namespace the users enters and how the environment is configured: Orange User will connect to mail-region.contoso.com as his namespace endpoint. CAS2010 in Site2 will authenticate the user, do a service discovery, and determine that the mailbox is located within the local AD site and retrieve the necessary data from the Exchange 2010 Mailbox server. Orange User will connect to mail.contoso.com as his namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site2, which does contain an OWA ExternalURL. CAS2010 in Site1 is not configured to do a cross-site silent redirection, therefore, the user is prompted to use the correct URL to access his mailbox data. Orange User will connect to mail.contoso.com as his namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site2, which does contain an OWA ExternalURL. CAS2010 in Site1 is configured to do a cross-site silent redirection, therefore, CAS2010 will initiate a single sign-on silent redirect (assumes FBA is enabled on source and target) to mail-region.contoso.com. CAS2010 in Site2 will then facilitate the request and retrieve the necessary data from the Exchange 2010 Mailbox server. Exchange ActiveSync For more information, see the article Upgrading Exchange ActiveSync to Exchange 2010. Red User’s ActiveSync client will connect to mail.contoso.com as the namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, determine that the mailbox is located within the local AD site and retrieve the necessary data from the Exchange 2010 Mailbox server. Blue User’s ActiveSync client will connect to mail.contoso.com as the namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site3, which does not contain any EAS ExternalURLs. CAS2010 in Site1 will issue a cross-site proxy the request to CAS2010 in Site3. CAS2010 in Site3 will retrieve the necessary data from the Exchange 2010 Mailbox server. For the Orange User, there are two possible scenarios: Orange User will connect to mail-region.contoso.com as his namespace endpoint. CAS2010 in Site2 will authenticate the user, do a service discovery, and determine that the mailbox is located within the local AD site and retrieve the necessary data from the Exchange 2010 Mailbox server. Orange User will connect to mail.contoso.com as his namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site2, which does contain an EAS ExternalURL. Assuming the device supports Autodiscover and is on a defined list of devices that supports the 451 redirect response, CAS2010 will issue a 451 response to the device, notifying the device it needs to use a new namespace, mail-region.contoso.com. CAS2010 in Site2 will then facilitate the request and retrieve the necessary data from the Exchange 2010 Mailbox server. If the device is not on the supported list, then CAS2010 in Site1 will proxy the request to CAS2010 in Site2 Exchange Web Services For the Red User, Autodiscover will return the mail.contoso.com namespace for the Exchange Web Service URL. CAS2010 in Site1 will service the request. For the Blue User, Autodiscover will return the mail.contoso.com namespace for the Exchange Web Service URL. CAS2010 will then proxy the request to an Exchange 2010 Client Access server located in Site3. For the Orange User, Autodiscover will return the mail-region.contoso.com namespace for the Exchange Web Service URL. CAS2010 in Site2 will service the request. Client Connectivity with Exchange 2016 in Site1 Exchange 2016 has now been deployed in Site1 following the guidance documented within the Exchange Deployment Assistant. As a result, Outlook Anywhere has been enabled on all Client Access servers within the infrastructure and the mail.contoso.com and autodiscover.contoso.com namespaces have been moved to resolve to Exchange 2016 Client Access component infrastructure. To understand the client connectivity now that Exchange 2016 exists in the environment, let’s look at the four users. Autodiscover The Autodiscover external namespace, autodiscover.contoso.com, as well as, the internal SCP records resolve to the MBX2016 infrastructure located in Site1. Outlook clients and ActiveSync clients (on initial configuration) will submit Autodiscover requests to the MBX2016 infrastructure and depending on the mailbox version, different behaviors occur: For mailboxes that exist on Exchange 2010, MBX2016 will proxy the request to an Exchange 2010 Client Access server that exists within the mailbox’s local site. This means that for Red User, this will be a local proxy to a CAS2010 in Site1. For Blue User and Orange User, this will be a cross-site proxy to a CAS2010 located in the user’s respective site. CAS2010 will then generate the Autodiscover response. For mailboxes that exist on Exchange 2016 (Purple User), MBX2016 will proxy the request to the Exchange 2016 Mailbox server that is hosting the active copy of the user’s mailbox which will generate the Autodiscover response. Internal Outlook Connectivity For internal Outlook clients using RPC/TCP connectivity whose mailboxes exist on Exchange 2010, they will still connect to the Exchange 2010 RPC Client Access array endpoint. When you have an Exchange 2016 mailbox you are using Outlook Anywhere (RPC/HTTP) or MAPI/HTTP, either within the corporate network or outside of the corporate network; RPC/TCP connectivity no longer exists for Exchange 2016 mailboxes. Important: When you introduce Exchange 2016 into a native Exchange 2010 environment, MAPI/HTTP will be enabled by default. Prior to moving any mailboxes to Exchange 2016, ensure you have configured your load balancer and/or firewall rules to allow traffic on /mapi/* via TCP443. In Exchange 2010, the way Outlook Anywhere was implemented is that you had one namespace you could configure. In Exchange 2016, you have both an internal host name and an external host name. Think of it as having two sets of Outlook Anywhere settings, one for when you are connected to the corporate domain, and another for when you are not. You will see this returned to the Outlook client in the Autodiscover response via what looks like a new provider, ExHTTP. However, ExHTTP isn’t an actual provider, it is a calculated set of values from the EXCH (internal Outlook Anywhere) and EXPR (External Outlook Anywhere) settings. To correctly use these settings, the Outlook client must be patched to the appropriate levels (see the Outlook Updates for more information). Outlook will process the ExHTTP in order – internal first and external second. Important: In the event that you are utilizing a split-brain DNS infrastructure, then you must use different names for Outlook Anywhere inside and out. Outlook will also prefer the internal settings over the external settings and since the same namespace is used for both, regardless of whether the client is internal or external, it will utilize only the internal authentication settings. By utilizing two namespaces for Outlook Anywhere, you can ensure that your internal clients can connect utilizing Kerberos authentication. The default Exchange 2016 internal Outlook Anywhere settings don’t require HTTPS. By not requiring SSL, the client should be able to connect and not get a certificate pop-up for the mail and directory connections. However, you will still have to deploy a certificate that is trusted by the client machine for Exchange Web Services and OAB downloads. In environments that are native Exchange 2010, when you introduce Exchange 2016, MAPI/HTTP will be enabled by default. As long as the client supports the protocol, once a mailbox is moved to Exchange 2016, the client will reconfigure itself to use MAPI/HTTP. Upon next boot of the client, MAPI/HTTP will be utilized. It is very important to ensure that you have the correct firewall and load balancer settings in place prior to moving mailboxes, otherwise client connectivity will fail. External Outlook Anywhere & MAPI/HTTP Connectivity In order to support access for Outlook Anywhere clients whose mailboxes are on legacy versions of Exchange, you will need to make some changes to your environment which are documented in the steps within the Exchange Deployment Assistant. Specifically, you will need to enable Outlook Anywhere on your legacy Client Access servers and enable NTLM in addition to basic authentication for the IIS Authentication Method. The Exchange 2016 Client Access component’s RPC proxy component sees the incoming connections, authenticates and chooses which server to route the request to (regardless of version), proxying the HTTP session to the endpoint (Exchange 2010 CAS or Exchange 2016 Mailbox server). Red User will connect to mail.contoso.com as his RPC proxy endpoint. MBX2016 in Site1 will determine the mailbox version is 2010 and that the mailbox database hosting the user’s mailbox is located in the local site. MBX2016 will proxy the request to CAS2010 in Site1. CAS2010 will de-encapsulate the RPC from the HTTP packet and obtain the data from the Exchange 2010 Mailbox server. Purple User will connect to mail.contoso.com as his RPC proxy or MAPI/HTTP endpoint. MBX2016 in Site1 will perform a local proxy request, proxying the HTTP session to the Mailbox 2016 server that hosts the active database copy in Site1. Blue User will connect to mail.contoso.com as his RPC proxy endpoint. MBX2016 in Site1 will determine the mailbox version is 2010 and that the mailbox database hosting the user’s mailbox is located in Site3. MBX2016 will proxy the request to CAS2010 in Site3. CAS2010 will de-encapsulate the RPC from the HTTP packet and obtain the data from the Exchange 2010 Mailbox server. Orange User will continue to access his mailbox using the Exchange 2010 regional namespace, mail-region.contoso.com. Outlook on the web For Outlook on the web, the user experience will depend on the mailbox version and where the mailbox is located. Red User will connect to mail.contoso.com as his namespace endpoint. MBX2016 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox version is 2010 and is located within the local AD site. MBX2016 will proxy the request to an Exchange 2010 Client Access server which will retrieve the necessary data from the Exchange 2010 Mailbox server. Purple User will connect to mail.contoso.com as his endpoint. MBX2016 in Site1 will perform a local proxy request, proxying the HTTP session to the Mailbox 2016 server that hosts the active database copy in Site1. Blue User will connect to mail.contoso.com as his namespace endpoint. MBX2016 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site3, which does not contain any OWA ExternalURLs. MBX2016 in Site1 will proxy the request to CAS2010 in Site3. CAS2010 in Site3 will retrieve the necessary data from the Exchange 2010 Mailbox server. For the Orange User, there are two possible scenarios: Orange User will connect to mail-region.contoso.com as his namespace endpoint. In this case, MBX2016 is not involved in any fashion. Orange User will connect to mail.contoso.com as his namespace endpoint. MBX2016 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site2, which does contain an OWA ExternalURL. MBX2016 in Site1 will initiate a single sign-on silent redirect (assumes FBA is enabled on source and target) to mail-region.contoso.com. CAS2010 in Site2 will then facilitate the request and retrieve the necessary data from the Exchange 2010 Mailbox server. Exchange ActiveSync For Exchange ActiveSync clients, the user experience will depend on the mailbox version and where the mailbox is located. In addition, Exchange 2016 no longer supports the 451 redirect response – Exchange 2016 will always proxy ActiveSync requests (except in hybrid scenarios, where redirection is allowed). Red User’s ActiveSync client will connect to mail.contoso.com as the namespace endpoint. MBX2016 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox version is 2010 and the mailbox is located within the local AD site. MBX2016 will proxy the request to an Exchange 2010 Client Access server which will retrieve the necessary data from the Exchange 2010 Mailbox server. Purple User’s ActiveSync client will connect to mail.contoso.com as his endpoint. MBX2016 in Site1 will perform a local proxy request, proxying the HTTP session to the Mailbox 2016 server that hosts the active database copy in Site1. Blue User’s ActiveSync client will connect to mail.contoso.com as the namespace endpoint. MBX2016 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site3. MBX2016 in Site1 will issue a cross-site proxy the request to CAS2010 in Site3. CAS2010 in Site3 will retrieve the necessary data from the Exchange 2010 Mailbox server. For the Orange User, there are two possible scenarios depending on how the device is configured: Orange User’s ActiveSync client is configured to connect to mail-region.contoso.com as the namespace endpoint. In this case, MBX2016 is not involved in any fashion. Note that any new device that is configured will automatically be configured to use mail-regi on.contoso.com. Orange User’s ActiveSync client is configured to connect to mail.contoso.com as the namespace endpoint. MBX2016 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox version is 2010 and the mailbox is located within another AD site. MBX2016 will issue a cross-site proxy request to an Exchange 2010 Client Access server that resides in the same site as the mailbox. Exchange Web Services Coexistence with Exchange Web Services is rather simple. For the Red User, Autodiscover will return the mail.contoso.com namespace for the Exchange Web Service URL. MBX2016 will then proxy the request to an Exchange 2010 Client Access server within the local site. For the Purple User, Autodiscover will return the mail.contoso.com namespace for the Exchange Web Service URL. MBX2016 in Site1 will perform a local proxy request, proxying the HTTP session to the Mailbox 2016 server that hosts the active database copy in Site1. For the Blue User, Autodiscover will return the mail.contoso.com namespace for the Exchange Web Service URL. MBX2016 will then proxy the request to an Exchange 2010 Client Access server located in Site3. For the Orange User, Autodiscover will return the mail-region.contoso.com namespace for the Exchange Web Service URL. Offline Address Book Like with Exchange Web Services, Autodiscover will provide the Offline Address Book URL. For the Red User, Autodiscover will return the mail.contoso.com namespace for the Offline Address Book URL. MBX2016 will then proxy the request to any Client Access server within the local site that is a web distribution point for the Offline Address Book in question. For the Purple User, Autodiscover will return the mail.contoso.com namespace for the Offline Address Book URL. MBX2016 will then proxy the request to the Exchange 2013/2016 Mailbox server that is hosting the active copy of an OABGEN mailbox that contains a copy of OAB that is closest to the user’s mailbox. For the Blue User, Autodiscover will return the mail.contoso.com namespace for the Offline Address Book URL. MBX2016 will then proxy the request to any Client Access server within the local site that is a web distribution point for the Offline Address Book in question. For the Orange User, Autodiscover will return the mail-region.contoso.com namespace for the Offline Address Book URL. How MBX2016 Picks a Target Legacy Exchange Server It’s important to understand that when MBX2016 proxies to a legacy Exchange Client Access server, it constructs a URL based on the server FQDN, not a load balanced namespace or the InternalURL value. But how does MBX2016 choose which legacy Client Access server to proxy the connection? When a MBX2016 starts up, it connects to Active Directory and enumerates a topology map to understand all the Client Access servers that exist within the environment. Every 50 seconds, MBX2016 will send a lightweight request to each protocol end point to all the Client Access servers in the topology map; these requests have a user agent string of HttpProxy.ClientAccessServer2010Ping. MBX2016 expects a response - a 200/300/400 response series indicates the target server is up for the protocol in question; a 502, 503, or 504 response indicates a failure. If a failure response occurs, MBX2016 immediately retries to determine if the error was a transient error. If this second attempt fails, MBX2016 marks the target CAS as down and excludes it from being a proxy target. At the next interval (50 seconds), MBX2016 will attempt to determine the health state of the down CAS to determine if it is available. The IIS log on a legacy Client Access server will contain the ping events. For example: 2015-08-11 14:00:00 W3SVC1 DF-C14-02 192.168.1.76 HEAD /ecp - 443 - 192.168.1.42 HTTP/1.1 HttpProxy.ClientAccessServer2010Ping - - coe-e16-1.coe.lab 302 0 0 277 170 0 2015-08-11 14:00:00 W3SVC1 DF-C14-02 192.168.1.76 HEAD /PowerShell - 443 - 192.168.1.27 HTTP/1.1 HttpProxy.ClientAccessServer2010Ping - - coe-e16-1.coe.lab 401 0 0 309 177 15 2015-08-11 14:00:00 W3SVC1 DF-C14-02 192.168.1.76 HEAD /EWS - 443 - 192.168.1.134 HTTP/1.1 HttpProxy.ClientAccessServer2010Ping - - coe-e16-1.coe.lab 401 0 0 245 170 0 2015-08-11 14:00:00 W3SVC1 DF-C14-02 192.168.1.76 GET /owa - 443 - 192.168.1.220 HTTP/1.1 HttpProxy.ClientAccessServer2010Ping - - coe-e16-1.coe.lab 301 0 0 213 169 171 2015-08-11 14:00:01 W3SVC1 DF-C14-02 192.168.1.76 HEAD /Microsoft-Server-ActiveSync/default.eas - 443 - 192.168.1.29 HTTP/1.1 HttpProxy.ClientAccessServer2010Ping - - coe-e16-1.coe.lab 401 2 5 293 194 31 2015-08-11 14:00:04 W3SVC1 DF-C14-02 192.168.1.76 HEAD /OAB - 443 - 10.166.18.213 HTTP/1.1 HttpProxy.ClientAccessServer2010Ping - - coe-e16-1.coe.lab 401 2 5 261 170 171 If for some reason, you would like to ensure a particular CAS2010 is never considered a proxy endpoint (or want to remove it for maintenance activities), you can do so by executing the following cmdlet on Exchange 2010: Set-ClientAccessServer <server> -IsOutofService $True IMAP & POP Coexistence All this discussion about HTTP-based clients is great, but what about POP and IMAP clients? Like the HTTP-based client counterparts, IMAP and POP clients are also proxied from the Exchange 2016 Client Access component to a target server (whether that be an Exchange 2016 Mailbox server or a legacy Client Access server). However, there is one key difference, there is no health-checking on the target IMAP/POP services. When the Exchange 2016 Client Access component receives a POP or IMAP request, it will authenticate the user and perform a service discovery. If the target mailbox is E2010, MBX2016 will enumerate the POP or IMAP InternalConnectionSettings property value for each Exchange 2010 Client Access server within the mailbox’s site. Therefore, it is important to ensure that the InternalConnectionSettings maps to the server's FQDN, and not a load-balanced namespace. MBX2016 will choose a server to proxy the request based on the incoming connection’s configuration. If the incoming connection is over an encrypted channel, MBX2016 will try to locate an SSL proxy target first, TLS next, plaintext lastly. If the incoming connection is over a plaintext channel, MBX2016 will try to locate a plaintext proxy target first, SSL next, TLS lastly. Important: Exchange 2016 Mailbox servers do not validate that the POP or IMAP services are actually running on the target Client Access servers. It's important, therefore, to ensure that the services are running on every legacy Client Access server if you have POP or IMAP clients in your environment. Conclusion Hopefully this information dispels some of the myths around proxying and redirection logic for Exchange 2016 when coexisting with Exchange 2010. Please let us know if you have any questions. Ross Smith IV Principal Program Manager Office 365 Customer ExperienceThe Exchange 2016 Preferred Architecture
The Preferred Architecture (PA) is the Exchange Engineering Team’s best practice recommendation for what we believe is the optimum deployment architecture for Exchange 2016, and one that is very similar to what we deploy in Office 365. While Exchange 2016 offers a wide variety of architectural choices for on-premises deployments, the architecture discussed below is our most scrutinized one ever. While there are other supported deployment architectures, they are not recommended. The PA is designed with several business requirements in mind, such as the requirement that the architecture be able to: Include both high availability within the datacenter, and site resilience between datacenters Support multiple copies of each database, thereby allowing for quick activation Reduce the cost of the messaging infrastructure Increase availability by optimizing around failure domains and reducing complexity The specific prescriptive nature of the PA means of course that not every customer will be able to deploy it (for example, customers without multiple datacenters). And some of our customers have different business requirements or other needs which necessitate a different architecture. If you fall into those categories, and you want to deploy Exchange on-premises, there are still advantages to adhering as closely as possible to the PA, and deviate only where your requirements widely differ. Alternatively, you can consider Office 365 where you can take advantage of the PA without having to deploy or manage servers. The PA removes complexity and redundancy where necessary to drive the architecture to a predictable recovery model: when a failure occurs, another copy of the affected database is activated. The PA is divided into four areas of focus: Namespace design Datacenter design Server design DAG design Namespace Design In the Namespace Planning and Load Balancing Principles articles, I outlined the various configuration choices that are available with Exchange 2016. For the namespace, the choices are to either deploy a bound namespace (having a preference for the users to operate out of a specific datacenter) or an unbound namespace (having the users connect to any datacenter without preference). The recommended approach is to utilize the unbounded model, deploying a single Exchange namespace per client protocol for the site resilient datacenter pair (where each datacenter is assumed to represent its own Active Directory site - see more details on that below). For example: autodiscover.contoso.com For HTTP clients: mail.contoso.com For IMAP clients: imap.contoso.com For SMTP clients: smtp.contoso.com Each Exchange namespace is load balanced across both datacenters in a layer 7 configuration that does not leverage session affinity, resulting in fifty percent of traffic being proxied between datacenters. Traffic is equally distributed across the datacenters in the site resilient pair, via round robin DNS, geo-DNS, or other similar solutions. From our perspective, the simpler solution is the least complex and easier to manage, so our recommendation is to leverage round robin DNS. For the Office Online Server farm, a namespace is deployed per datacenter, with the load balancer utilizing layer 7, maintaining session affinity using cookie based persistence. Figure 1: Namespace Design in the Preferred Architecture In the event that you have multiple site resilient datacenter pairs in your environment, you will need to decide if you want to have a single worldwide namespace, or if you want to control the traffic to each specific datacenter by using regional namespaces. Ultimately your decision depends on your network topology and the associated cost with using an unbound model; for example, if you have datacenters located in North America and Europe, the network link between these regions might not only be costly, but it might also have high latency, which can introduce user pain and operational issues. In that case, it makes sense to deploy a bound model with a separate namespace for each region. However, options like geographical DNS offer you the ability to deploy a single unified namespace, even when you have costly network links; geo-DNS allows you to have your users directed to the closest datacenter based on their client’s IP address. Figure 2: Geo-distributed Unbound Namespace Site Resilient Datacenter Pair Design To achieve a highly available and site resilient architecture, you must have two or more datacenters that are well-connected (ideally, you want a low round-trip network latency, otherwise replication and the client experience are adversely affected). In addition, the datacenters should be connected via redundant network paths supplied by different operating carriers. While we support stretching an Active Directory site across multiple datacenters, for the PA we recommend that each datacenter be its own Active Directory site. There are two reasons: Transport site resilience via Shadow Redundancy and Safety Net can only be achieved when the DAG has members located in more than one Active Directory site. Active Directory has published guidance that states that subnets should be placed in different Active Directory sites when the round trip latency is greater than 10ms between the subnets. Server Design In the PA, all servers are physical servers. Physical hardware is deployed rather than virtualized hardware for two reasons: The servers are scaled to use 80% of resources during the worst-failure mode. Virtualization adds an additional layer of management and complexity, which introduces additional recovery modes that do not add value, particularly since Exchange provides that functionality. Commodity server platforms are used in the PA. Commodity platforms are and include: 2U, dual socket servers (20-24 cores) up to 192GB of memory a battery-backed write cache controller 12 or more large form factor drive bays within the server chassis Additional drive bays can be deployed per-server depending on the number of mailboxes, mailbox size, and the server’s scalability. Each server houses a single RAID1 disk pair for the operating system, Exchange binaries, protocol/client logs, and transport database. The rest of the storage is configured as JBOD, using large capacity 7.2K RPM serially attached SCSI (SAS) disks (while SATA disks are also available, the SAS equivalent provides better IO and a lower annualized failure rate). Each disk that houses an Exchange database is formatted with ReFS (with the integrity feature disabled) and the DAG is configured such that AutoReseed formats the disks with ReFS: Set-DatabaseAvailabilityGroup <DAG> -FileSystem ReFS BitLocker is used to encrypt each disk, thereby providing data encryption at rest and mitigating concerns around data theft or disk replacement. For more information, see Enabling BitLocker on Exchange Servers. To ensure that the capacity and IO of each disk is used as efficiently as possible, four database copies are deployed per-disk. The normal run-time copy layout ensures that there is no more than a single active copy per disk. At least one disk in the disk pool is reserved as a hot spare. AutoReseed is enabled and quickly restores database redundancy after a disk failure by activating the hot spare and initiating database copy reseeds. Database Availability Group Design Within each site resilient datacenter pair you will have one or more DAGs. DAG Configuration As with the namespace model, each DAG within the site resilient datacenter pair operates in an unbound model with active copies distributed equally across all servers in the DAG. This model: Ensures that each DAG member’s full stack of services (client connectivity, replication pipeline, transport, etc.) is being validated during normal operations. Distributes the load across as many servers as possible during a failure scenario, thereby only incrementally increasing resource use across the remaining members within the DAG. Each datacenter is symmetrical, with an equal number of DAG members in each datacenter. This means that each DAG has an even number of servers and uses a witness server for quorum maintenance. The DAG is the fundamental building block in Exchange 2016. With respect to DAG size, a larger DAG provides more redundancy and resources. Within the PA, the goal is to deploy larger DAGs (typically starting out with an eight member DAG and increasing the number of servers as required to meet your requirements). You should only create new DAGs when scalability introduces concerns over the existing database copy layout. DAG Network Design The PA leverages a single, non-teamed network interface for both client connectivity and data replication. A single network interface is all that is needed because ultimately our goal is to achieve a standard recovery model regardless of the failure - whether a server failure occurs or a network failure occurs, the result is the same: a database copy is activated on another server within the DAG. This architectural change simplifies the network stack, and obviates the need to manually eliminate heartbeat cross-talk. Note: While your environment may not use IPv6, IPv6 remains enabled per IPv6 support in Exchange. Witness Server Placement Ultimately, the placement of the witness server determines whether the architecture can provide automatic datacenter failover capabilities or whether it will require a manual activation to enable service in the event of a site failure. If your organization has a third location with a network infrastructure that is isolated from network failures that affect the site resilient datacenter pair in which the DAG is deployed, then the recommendation is to deploy the DAG’s witness server in that third location. This configuration gives the DAG the ability to automatically failover databases to the other datacenter in response to a datacenter-level failure event, regardless of which datacenter has the outage. If your organization does not have a third location, consider placing the witness in Azure; alternatively, place the witness server in one of the datacenters within the site resilient datacenter pair. If you have multiple DAGs within the site resilient datacenter pair, then place the witness server for all DAGs in the same datacenter (typically the datacenter where the majority of the users are physically located). Also, make sure the Primary Active Manager (PAM) for each DAG is also located in the same datacenter. Data Resiliency Data resiliency is achieved by deploying multiple database copies. In the PA, database copies are distributed across the site resilient datacenter pair, thereby ensuring that mailbox data is protected from software, hardware and even datacenter failures. Each database has four copies, with two copies in each datacenter, which means at a minimum, the PA requires four servers. Out of these four copies, three of them are configured as highly available. The fourth copy (the copy with the highest Activation Preference number) is configured as a lagged database copy. Due to the server design, each copy of a database is isolated from its other copies, thereby reducing failure domains and increasing the overall availability of the solution as discussed in DAG: Beyond the “A”. The purpose of the lagged database copy is to provide a recovery mechanism for the rare event of system-wide, catastrophic logical corruption. It is not intended for individual mailbox recovery or mailbox item recovery. The lagged database copy is configured with a seven day ReplayLagTime. In addition, the Replay Lag Manager is also enabled to provide dynamic log file play down for lagged copies when availability is compromised. By using the lagged database copy in this manner, it is important to understand that the lagged database copy is not a guaranteed point-in-time backup. The lagged database copy will have an availability threshold, typically around 90%, due to periods where the disk containing a lagged copy is lost due to disk failure, the lagged copy becoming an HA copy (due to automatic play down), as well as, the periods where the lagged database copy is re-building the replay queue. To protect against accidental (or malicious) item deletion, Single Item Recovery or In-Place Hold technologies are used, and the Deleted Item Retention window is set to a value that meets or exceeds any defined item-level recovery SLA. With all of these technologies in play, traditional backups are unnecessary; as a result, the PA leverages Exchange Native Data Protection. Office Online Server Design At a minimum, you will want to deploy two Office Online Servers in each datacenter that hosts Exchange 2016 servers. Each Office Online Server should have 8 processor cores, 32GB of memory and at least 40GB of space dedicated for log files. Note: The Office Online Server infrastructure does not need to be exclusive to Exchange. As such, the hardware guidance takes into account usage by SharePoint and Skype for Business. Be sure to work with any other teams using the Office Online Server infrastructure to ensure the servers are adequately sized for your specific deployment. The Exchange servers within a particular datacenter are configured to use the local Office Online Server farm via the following cmdlet: Set-MailboxServer <East MBX Server> –WACDiscoveryEndPoint https://oos-east.contoso.com/hosting/discovery Summary Exchange Server 2016 continues in the investments introduced in previous versions of Exchange by reducing the server role architecture complexity, aligning with the Preferred Architecture and Office 365 design principles, and improving coexistence with Exchange Server 2013. These changes simplify your Exchange deployment, without decreasing the availability or the resiliency of the deployment. And in some scenarios, when compared to previous generations, the PA increases availability and resiliency of your deployment. Ross Smith IV Principal Program Manager Office 365 Customer ExperienceClient Connectivity in an Exchange 2013 Coexistence Environment
This article is part 3 in a series that discusses namespace planning, load balancing principles, client connectivity, and certificate planning. Over the last several months, we have routinely fielded questions on how various clients connect to the infrastructure once Exchange 2013 is deployed. Our goal with this article is to articulate the various connectivity scenarios you may encounter in your designs. To that end, this article will begin with a walk through of a deployment that consists of Exchange 2007 and Exchange 2010 in a multi-site architecture and show how the connectivity changes with the introduction of Exchange 2013. Existing Environment Figure 1: Exchange 2007 & Exchange 2010 Multi-Site Architecture As you can see from the above diagram, this environment contains three Active Directory sites: Internet Facing AD Site (Site1) - This is the main AD site in the environment and has exposure to the Internet. This site also has a mix of Exchange 2007 and Exchange 2010 servers. There are three namespaces associated with this location – mail.contoso.com and autodiscover.contoso.com resolve to the CAS2010 infrastructure and legacy.contoso.com resolves to the CAS2007 infrastructure. Regional Internet Facing AD Site (Site2) - This is an AD site that has exposure to the Internet. This site has Exchange 2010 servers. The primary namespace is mail-region.contoso.com and resolves to the CAS2010 infrastructure located within this AD site. Non-Internet Facing AD Site (Site3) - This is an AD site that does not have exposure to the Internet. This site contains Exchange 2010 infrastructure. Note: The term, Internet Facing AD Site, simply means any Active Directory site containing Client Access servers whose virtual directories have the ExternalURL property populated. Similarly, the term, Non-Internet Facing AD Site, simply means any Active Directory site containing Client Access servers whose virtual directories do not have ExternalURL property populated. To understand the client connectivity before we instantiate Exchange 2013 into the environment, let’s look at the four users. Autodiscover The Autodiscover namespace, autodiscover.contoso.com, as well as, the internal SCP records resolve to the CAS2010 infrastructure located in Site1. Outlook clients and ActiveSync clients (on initial configuration) will submit Autodiscover requests to the CAS2010 infrastructure and retrieve configuration settings based on their mailbox’s location. The Autodiscover service on Exchange 2010 can process Autodiscover requests for both Exchange 2007 and Exchange 2010 mailboxes. Note: The recommended practice is to configure the 2007 and 2010 Client Access server’s AutoDiscoverServiceInternalUri value (which is the property value you use to set the SCP record) to point to autodiscover.contoso.com, assuming split-brain DNS is in place. If split-brain DNS is not configured, then set AutoDiscoverServiceInternalUri to a value that resolves to the load balanced VIP for the 2010 Client Access servers in your environment. For more information on how Autodiscover requests are performed, see the whitepaper, Understanding the Exchange 2010 Autodiscover Service. Internal Outlook Connectivity For internal Outlook clients using RPC/TCP connectivity whose mailboxes exist on Exchange 2010, they will connect to the Exchange 2010 RPC Client Access array endpoint (assuming one exists). Keep in mind the importance of configuring the RPC Client Access array endpoint correctly, as documented in Ambiguous URLs and their effect on Exchange 2010 to Exchange 2013 Migrations. For internal Outlook clients using RPC/TCP connectivity whose mailboxes exist on Exchange 2007, they will connect directly to the Exchange 2007 Mailbox server instance hosting the mailbox. Outlook Anywhere Red User will connect to mail.contoso.com as his RPC proxy endpoint. CAS2010 in Site1 will de-encapsulate the RPC data embedded within the HTTP packet and since the target mailbox database is located within the local site, will retrieve the necessary data from the local Exchange 2010 Mailbox server. Purple User will connect to mail.contoso.com as his RPC proxy endpoint. CAS2010 in Site1 will de-encapsulate the RPC data embedded within the HTTP packet, determine that the mailbox server is located on an Exchange 2007 server, and proxy the Outlook RPC data to the target Exchange 2007 Mailbox server. Blue User will connect to mail.contoso.com as his RPC proxy endpoint. CAS2010 in Site1 will de-encapsulate the RPC data embedded within the HTTP packet, determine that the mailbox server hosting the mailbox is located in another AD site (in this case Site3) and proxy the Outlook RPC data to the target Exchange 2010 Client Access server. Orange User will connect to mail-region.contoso.com as his RPC proxy endpoint. CAS2010 in Site2 will de-encapsulate the RPC data embedded within the HTTP packet and since the target mailbox database is located within the local site, will retrieve the necessary data from the local Exchange 2010 Mailbox server. Note: In addition to the mail and directory connections, Outlook Anywhere clients also utilize Exchange Web Services and an Offline Address Book, which are provided via the Autodiscover response. Outlook Web App For more information, see the article Upgrading Outlook Web App to Exchange 2010. Red User will connect to mail.contoso.com as his namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, determine that the mailbox is located within the local AD site and retrieve the necessary data from the Exchange 2010 Mailbox server. Purple User will connect to mail.contoso.com as his namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within the local AD site on an Exchange 2007 Mailbox server. CAS2010 will initiate a single sign-on silent redirect (assumes FBA is enabled on source and target) to legacy.contoso.com. CAS2007 will then process the request and retrieve the necessary data from the Exchange 2007 Mailbox server. Blue User will connect to mail.contoso.com as his namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site3, which does not contain any OWA ExternalURLs. CAS2010 in Site1 will proxy the request to CAS2010 in Site3. CAS2010 in Site3 will retrieve the necessary data from the Exchange 2010 Mailbox server. For the Orange User, there are three possible scenarios depending on what namespace the users enters and how the environment is configured: Orange User will connect to mail-region.contoso.com as his namespace endpoint. CAS2010 in Site2 will authenticate the user, do a service discovery, and determine that the mailbox is located within the local AD site and retrieve the necessary data from the Exchange 2010 Mailbox server. Orange User will connect to mail.contoso.com as his namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site2, which does contain an OWA ExternalURL. CAS2010 in Site1 is not configured to do a cross-site silent redirection, therefore, the user is prompted to use the correct URL to access his mailbox data. Orange User will connect to mail.contoso.com as his namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site2, which does contain an OWA ExternalURL. CAS2010 in Site1 is configured to do a cross-site silent redirection, therefore, CAS2010 will initiate a single sign-on silent redirect (assumes FBA is enabled on source and target) to mail-region.contoso.com. CAS2010 in Site2 will then facilitate the request and retrieve the necessary data from the Exchange 2010 Mailbox server. Exchange ActiveSync For more information, see the article Upgrading Exchange ActiveSync to Exchange 2010. Red User’s ActiveSync client will connect to mail.contoso.com as the namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, determine that the mailbox is located within the local AD site and retrieve the necessary data from the Exchange 2010 Mailbox server. Purple User’s ActiveSync client will connect to mail.contoso.com as the namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within the local AD site on an Exchange 2007 Mailbox server. CAS2010 proxies the request to CAS2007. Blue User’s ActiveSync client will connect to mail.contoso.com as the namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site3, which does not contain any EAS ExternalURLs. CAS2010 in Site1 will issue a cross-site proxy the request to CAS2010 in Site3. CAS2010 in Site3 will retrieve the necessary data from the Exchange 2010 Mailbox server. For the Orange User, there are two possible scenarios: Orange User will connect to mail-region.contoso.com as his namespace endpoint. CAS2010 in Site2 will authenticate the user, do a service discovery, and determine that the mailbox is located within the local AD site and retrieve the necessary data from the Exchange 2010 Mailbox server. Orange User will connect to mail.contoso.com as his namespace endpoint. CAS2010 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site2, which does contain an EAS ExternalURL. Assuming the device supports Autodiscover and is on a defined list of devices that supports the 451 redirect response, CAS2010 will issue a 451 response to the device, notifying the device it needs to use a new namespace, mail-region.contoso.com. CAS2010 in Site2 will then facilitate the request and retrieve the necessary data from the Exchange 2010 Mailbox server. If the device is not on the supported list, then CAS2010 in Site1 will proxy the request to CAS2010 in Site2 Exchange Web Services For the Red User, Autodiscover will return the mail.contoso.com namespace for the Exchange Web Service URL. CAS2010 in Site1 will service the request. For the Blue User, Autodiscover will return the mail.contoso.com namespace for the Exchange Web Service URL. CAS2010 will then proxy the request to an Exchange 2010 Client Access server located in Site3. For the Purple User, Autodiscover will provide back the legacy.contoso.com namespace for the Exchange Web Service URL. CAS2007 in Site1 will service the request. For the Orange User, Autodiscover will return the mail-region.contoso.com namespace for the Exchange Web Service URL. CAS2010 in Site2 will service the request. Client Connectivity with Exchange 2013 in Site1 Exchange 2013 has now been deployed in Site1 following the guidance documented within the Exchange Deployment Assistant. As a result, Outlook Anywhere has been enabled on all Client Access servers within the infrastructure and the mail.contoso.com and autodiscover.contoso.com namespaces have been moved to resolve to Exchange 2013 Client Access server infrastructure. Figure 2: Exchange 2013 Coexistence with Exchange 2007 & Exchange 2010 in a Multi-Site Architecture To understand the client connectivity now that Exchange 2013 exists in the environment, let’s look at the four users. Autodiscover The Autodiscover external namespace, autodiscover.contoso.com, as well as, the internal SCP records resolve to the CAS2013 infrastructure located in Site1. Outlook clients and ActiveSync clients (on initial configuration) will submit Autodiscover requests to the CAS2013 infrastructure and depending on the mailbox version, different behaviors occur: For mailboxes that exist on Exchange 2010, CAS2013 will proxy the request to an Exchange 2010 Client Access server that exists within the mailbox’s local site. This means that for Red User, this will be a local proxy to a CAS2010 in Site1. For Blue User and Orange User, this will be a cross-site proxy to a CAS2010 located in the user’s respective site. CAS2010 will then generate the Autodiscover response. For mailboxes that exist on Exchange 2007, CAS2013 will proxy the request to an Exchange 2013 Mailbox server in the local site, which will generate the Autodiscover response. This means for Purple User, the MBX2013 server in Site1 will generate the response. For mailboxes that exist on Exchange 2013, CAS2013 will proxy the request to the Exchange 2013 Mailbox server that is hosting the active copy of the user’s mailbox which will generate the Autodiscover response. Internal Outlook Connectivity For internal Outlook clients using RPC/TCP connectivity whose mailboxes exist on Exchange 2010, they will still connect to the Exchange 2010 RPC Client Access array endpoint. For internal Outlook clients using RPC/TCP connectivity whose mailboxes exist on Exchange 2007, they will still connect directly to the Exchange 2007 Mailbox server instance hosting the mailbox. When you have an Exchange 2013 mailbox you are using Outlook Anywhere, both within the corporate network and outside of the corporate network; RPC/TCP connectivity no longer exists for Exchange 2013 mailboxes. In Exchange 2007/2010, the way Outlook Anywhere was implemented is that you had one namespace you could configure. In Exchange 2013, you have both an internal host name and an external host name. Think of it as having two sets of Outlook Anywhere settings, one for when you are connected to the corporate domain, and another for when you are not. You will see this returned to the Outlook client in the Autodiscover response via what looks like a new provider, ExHTTP. However, ExHTTP isn’t an actual provider, it is a calculated set of values from the EXCH (internal Outlook Anywhere) and EXPR (External Outlook Anywhere) settings. To correctly use these settings, the Outlook client must be patched to the appropriate levels (see the Exchange 2013 System Requirements for more information). Outlook will process the ExHTTP in order – internal first and external second. Important: In the event that you are utilizing a split-brain DNS infrastructure, then you must utilize the same authentication value for both your internal and external Outlook Anywhere settings, or switch to use different names for Outlook Anywhere inside and out. Outlook gives priority to the internal settings over the external settings and since the same namespace is used for both, regardless of whether the client is internal or external, it will utilize only the internal authentication settings. The default Exchange 2013 internal Outlook Anywhere settings don’t require HTTPS. By not requiring SSL, the client should be able to connect and not get a certificate pop-up for the mail and directory connections. However, you will still have to deploy a certificate that is trusted by the client machine for Exchange Web Services and OAB downloads. External Outlook Connectivity In order to support access for Outlook Anywhere clients whose mailboxes are on legacy versions of Exchange, you will need to make some changes to your environment which are documented in the steps within the Exchange Deployment Assistant. Specifically, you will need to enable Outlook Anywhere on your legacy Client Access servers and enable NTLM in addition to basic authentication for the IIS Authentication Method. The Exchange 2013 Client Access server’s RPC proxy component sees the incoming connections, authenticates and chooses which server to route the request to (regardless of version), proxying the HTTP session to the endpoint (legacy CAS or Exchange 2013 Mailbox server). Red User will connect to mail.contoso.com as his RPC proxy endpoint. CAS2013 in Site1 will determine the mailbox version is 2010 and that the mailbox database hosting the user’s mailbox is located in the local site. CAS2013 will proxy the request to CAS2010 in Site1. CAS2010 will de-encapsulate the RPC from the HTTP packet and obtain the data from the Exchange 2010 Mailbox server. Purple User will connect to mail.contoso.com as his RPC proxy endpoint. CAS2013 in Site1 will determine the mailbox version is 2007 and that the mailbox database hosting the user’s mailbox is located in the local site. CAS2013 will proxy the request to CAS2007 in Site1. CAS2007 will de-encapsulate the RPC from the HTTP packet and obtain the data from the Exchange 2007 Mailbox server. Blue User will connect to mail.contoso.com as his RPC proxy endpoint. CAS2013 in Site1 will determine the mailbox version is 2010 and that the mailbox database hosting the user’s mailbox is located in Site3. CAS2013 will proxy the request to CAS2010 in Site3. CAS2010 will de-encapsulate the RPC from the HTTP packet and obtain the data from the Exchange 2010 Mailbox server. Orange User will continue to access his mailbox using the Exchange 2010 regional namespace, mail-region.contoso.com. Outlook Web App For Outlook Web App, the user experience will depend on the mailbox version and where the mailbox is located. Red User will connect to mail.contoso.com as his namespace endpoint. CAS2013 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox version is 2010 and is located within the local AD site. CAS2013 will proxy the request to an Exchange 2010 Client Access server which will retrieve the necessary data from the Exchange 2010 Mailbox server. Purple User will connect to mail.contoso.com as his namespace endpoint. CAS2013 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within the local AD site on an Exchange 2007 Mailbox server. CAS2013 will initiate a single sign-on silent redirect (assumes FBA is enabled on source and target) to legacy.contoso.com. CAS2007 will then facilitate the request and retrieve the necessary data from the Exchange 2007 Mailbox server. Blue User will connect to mail.contoso.com as his namespace endpoint. CAS2013 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site3, which does not contain any OWA ExternalURLs. CAS2013 in Site1 will proxy the request to CAS2010 in Site3. CAS2010 in Site3 will retrieve the necessary data from the Exchange 2010 Mailbox server. For the Orange User, there are two possible scenarios: Orange User will connect to mail-region.contoso.com as his namespace endpoint. In this case, CAS2013 is not involved in any fashion. Orange User will connect to mail.contoso.com as his namespace endpoint. CAS2013 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site2, which does contain an OWA ExternalURL. CAS2013 in Site1 will initiate a single sign-on silent redirect (assumes FBA is enabled on source and target) to mail-region.contoso.com. CAS2010 in Site2 will then facilitate the request and retrieve the necessary data from the Exchange 2010 Mailbox server. Note: Let’s assume that Site3 contains Exchange 2007 servers as well. In this scenario, CAS2013 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox version is 2007 and the mailbox is located in Site3. CAS2013 will issue a single sign-on silent redirect to legacy.contoso.com. CAS2007 in Site1 will authenticate the user and proxy the request to the Exchange 2007 Client Access server infrastructure in Site3. Exchange ActiveSync For Exchange ActiveSync clients, the user experience will depend on the mailbox version and where the mailbox is located. In addition, Exchange 2013 no longer supports the 451 redirect response – Exchange 2013 will always proxy ActiveSync requests. Red User’s ActiveSync client will connect to mail.contoso.com as the namespace endpoint. CAS2013 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox version is 2010 and the mailbox is located within the local AD site. CAS2013 will proxy the request to an Exchange 2010 Client Access server which will retrieve the necessary data from the Exchange 2010 Mailbox server. Purple User’s ActiveSync client will connect to mail.contoso.com as the namespace endpoint. CAS2013 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox version is 2007. CAS2013 will proxy the request to a local Exchange 2013 Mailbox server. The Exchange 2013 Mailbox server will send the request to an Exchange 2007 Client Access server that exists within the mailbox’s site (specifically, the InternalURL value of the Microsoft-Server-ActiveSync virtual directory on CAS2007), which will retrieve the data from the Exchange 2007 Mailbox server. Blue User’s ActiveSync client will connect to mail.contoso.com as the namespace endpoint. CAS2013 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox is located within Site3. CAS2013 in Site1 will issue a cross-site proxy the request to CAS2010 in Site3. CAS2010 in Site3 will retrieve the necessary data from the Exchange 2010 Mailbox server. For the Orange User, there are two possible scenarios depending on how the device is configured: Orange User’s ActiveSync client is configured to connect to mail-region.contoso.com as the namespace endpoint. In this case, CAS2013 is not involved in any fashion. Note that any new device that is configured will automatically be configured to use mail-region.contoso.com. Orange User’s ActiveSync client is configured to connect to mail.contoso.com as the namespace endpoint. CAS2013 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox version is 2010 and the mailbox is located within another AD site. CAS2013 will issue a cross-site proxy request to an Exchange 2010 Client Access server that resides in the same site as the mailbox. Note: Let’s assume that Site3 contains Exchange 2007 servers as well. In this scenario, CAS2013 in Site1 will authenticate the user, do a service discovery, and determine that the mailbox version is 2007 and the mailbox is located in Site3. CAS2013 will proxy the request to a local Exchange 2013 Mailbox server. The Exchange 2013 Mailbox server will send the request to an Exchange 2007 Client Access server that exists within the mailbox’s site, which will retrieve the data from the Exchange 2007 Mailbox server. Exchange Web Services Coexistence with Exchange Web Services is rather simple. For the Red User, Autodiscover will return the mail.contoso.com namespace for the Exchange Web Service URL. CAS2013 will then proxy the request to an Exchange 2010 Client Access server within the local site. For the Purple User, Autodiscover will return the legacy.contoso.com namespace for the Exchange Web Service URL. For the Blue User, Autodiscover will return the mail.contoso.com namespace for the Exchange Web Service URL. CAS2013 will then proxy the request to an Exchange 2010 Client Access server located in Site3. For the Orange User, Autodiscover will return the mail-region.contoso.com namespace for the Exchange Web Service URL. Note: Let’s assume that Site3 contains Exchange 2007 servers as well. In this scenario, the Autodiscover response will provide back the legacy.contoso.com namespace for the Exchange Service URL. CAS2007 in Site1 will proxy the request to an Exchange 2007 Client Access server that exists within the mailbox’s site, which will retrieve the data from the Exchange 2007 Mailbox server. This is why you cannot remove Exchange 2007 from the Internet-facing Active Directory site as long as Exchange 2007 exists in non-Internet facing Active Directory sites. Offline Address Book Like with Exchange Web Services, Autodiscover will provide the Offline Address Book URL. For the Red User, Autodiscover will return the mail.contoso.com namespace for the Offline Address Book URL. CAS2013 will then proxy the request to any Client Access server within the local site that is a web distribution point for the Offline Address Book in question. For the Purple User, Autodiscover will return the legacy.contoso.com namespace for the Offline Address Book URL. For the Blue User, Autodiscover will return the mail.contoso.com namespace for the Offline Address Book URL. CAS2013 will then proxy the request to any Client Access server within the local site that is a web distribution point for the Offline Address Book in question. For the Orange User, Autodiscover will return the mail-region.contoso.com namespace for the Offline Address Book URL. Note: Let’s assume that Site3 contains Exchange 2007 servers as well. In this scenario, the Autodiscover response will provide back the legacy.contoso.com namespace for the Offline Address Book URL. This is why you cannot remove Exchange 2007 from the Internet-facing Active Directory site as long as Exchange 2007 exists in non-Internet facing Active Directory sites. How CAS2013 Picks a Target Legacy Exchange Server It’s important to understand that when CAS2013 proxies to a legacy Exchange Client Access server, it constructs a URL based on the server FQDN, not a load balanced namespace or the InternalURL value.But how does CAS2013 choose which legacy Client Access server to proxy the connection? When a CAS2013 starts up, it connects to Active Directory and enumerates a topology map to understand all the Client Access servers that exist within the environment. Every 50 seconds, CAS2013 will send a lightweight request to each protocol end point to all the Client Access servers in the topology map; these requests have a user agent string of HttpProxy.ClientAccessServer2010Ping (yes, even Exchange 2007 servers are targeted with that user string). CAS2013 expects a response - a 200/300/400 response series indicates the target server is up for the protocol in question; a 502, 503, or 504 response indicates a failure. If a failure response occurs, CAS2013 immediately retries to determine if the error was a transient error. If this second attempt fails, CAS2013 marks the target CAS as down and excludes it from being a proxy target. At the next interval (50 seconds), CAS2013 will attempt to determine the health state of the down CAS to determine if it is available. The IIS log on a legacy Client Access server will contain the ping events. For example: 2014-03-11 14:00:00 W3SVC1 DF-C14-02 157.54.7.76 HEAD /ecp - 443 - 192.168.1.42 HTTP/1.1 HttpProxy.ClientAccessServer2010Ping - - coe-e14-1.coe.lab 302 0 0 277 170 0 2014-03-11 14:00:00 W3SVC1 DF-C14-02 157.54.7.76 HEAD /PowerShell - 443 - 192.168.1.27 HTTP/1.1 HttpProxy.ClientAccessServer2010Ping - - coe-e14-1.coe.lab 401 0 0 309 177 15 2014-03-11 14:00:00 W3SVC1 DF-C14-02 157.54.7.76 HEAD /EWS - 443 - 192.168.1.134 HTTP/1.1 HttpProxy.ClientAccessServer2010Ping - - coe-e14-1.coe.lab 401 0 0 245 170 0 2014-03-11 14:00:00 W3SVC1 DF-C14-02 157.54.7.76 GET /owa - 443 - 192.168.1.220 HTTP/1.1 HttpProxy.ClientAccessServer2010Ping - - coe-e14-1.coe.lab 301 0 0 213 169 171 2014-03-11 14:00:01 W3SVC1 DF-C14-02 157.54.7.76 HEAD /Microsoft-Server-ActiveSync/default.eas - 443 - 192.168.1.29 HTTP/1.1 HttpProxy.ClientAccessServer2010Ping - - coe-e14-1.coe.lab 401 2 5 293 194 31 2014-03-11 14:00:04 W3SVC1 DF-C14-02 157.54.7.76 HEAD /OAB - 443 - 10.166.18.213 HTTP/1.1 HttpProxy.ClientAccessServer2010Ping - - coe-e14-1.coe.lab 401 2 5 261 170 171 If for some reason, you would like to ensure a particular CAS2010 is never considered a proxy endpoint (or want to remove it for maintenance activities), you can do so by executing the following cmdlet on Exchange 2010 (note that this feature does not exist on Exchange 2007): Set-ClientAccessServer <server> -IsOutofService $True IMAP & POP Coexistence All this discussion about HTTP-based clients is great, but what about POP and IMAP clients? Like the HTTP-based client counterparts, IMAP and POP clients are also proxied from the Exchange 2013 Client Access server to a target server (whether that be an Exchange 2013 Mailbox server or a legacy Client Access server). However, there is one key difference, there is no health-checking on the target IMAP/POP services. When the Exchange 2013 Client Access server receives a POP or IMAP request, it will authenticate the user and perform a service discovery. If the target mailbox is E2010, CAS2013 will enumerate the POP or IMAP InternalConnectionSettings property value for each Exchange 2010 Client Access server within the mailbox’s site. Therefore, it is important to ensure that the InternalConnectionSettings maps to the server's FQDN, and not a load-balanced namespace. If the target mailbox is E2007, CAS2013 will enumerate each Exchange 2007 Client Access server’s server FQDN within the mailbox’s site. CAS2013 will choose a server to proxy the request based on the incoming connection’s configuration. If the incoming connection is over an encrypted channel, CAS2013 will try to locate an SSL proxy target first, TLS next, plaintext lastly. If the incoming connection is over a plaintext channel, CAS2013 will try to locate a plaintext proxy target first, SSL next, TLS lastly. Important: Exchange 2013 Client Access servers do not validate that the POP or IMAP services are actually running on the target Client Access servers. It's important, therefore, to ensure that the services are running on every legacy Client Access server if you have POP or IMAP clients in your environment. Conclusion Hopefully this information dispels some of the myths around proxying and redirection logic for Exchange 2013 when coexisting with either Exchange 2007 or Exchange 2010. Please let us know if you have any questions. Ross Smith IV Principal Program Manager Office 365 Customer Experience Updates 3/14/2014: Added section on IMAP/POP coexistence 3/25/2014: Added detail that MBX2013 proxies to the CAS2007 MSAS InternalURL for 2007 EAS mailbox accessManaging OAB in Exchange Server 2013
The Exchange team blog article OAB in Exchange Server 2013 introduced the new Offline Address Book (OAB) generation and distribution architecture in Exchange Server 2013. Take a few moments to visit the article if you haven’t seen it yet or re-visit it for a quick refresher. The OAB management and administration is different in Exchange 2013 because of architecture changes. Additionally, the new Exchange Admin Center does not currently have options for managing OABs. This means that, at this time, you will need to use Exchange Management Shell for OAB-related tasks. This article takes you through commonly performed tasks in OAB administration and has a couple of real life scenarios to help understand the tasks better. Note: If you are in multi-forest Active Directory domain environment, make sure the Shell session has ViewEntireForest is enabled, else some of the commands in the article won’t return any output. Command to enable ViewEntireForest: Set-ADServerSettings -ViewEntireForest $true Creating a new OAB Creating a new OAB in Exchange 2013 no longer uses the -Server parameter. In order to create a new OAB, you should only specify the address lists to be required. The following example creates OAB for address list named “Global Address List FAB” New-OfflineAddressBook -Name OAB-FAB -AddressLists "Global Address List FAB" Identify the OAB generation server(s) The arbitration mailboxes in Exchange Server 2013 are assigned certain “Persisted capability” that defines the purpose/function of the arbitration mailbox. An arbitration mailbox with Persisted Capability “OrganizationCapabilityOABGen” is responsible for OAB generation. We will refer this mailbox as “Organization Mailbox” throughout the article. Exchange Server 2013 mailbox server hosting the Organization Mailbox will generate all OAB’s defined in the environment. For a non-DAG environment, use following command to identify the OAB Generation servers: Get-Mailbox -Arbitration | where {$_.PersistedCapabilities -like "*oab*"} | ft name,servername For a DAG environment, identifying OAB generation server(s) is a two-step process. Step1: Identify the mailbox database hosting organization mailbox with OAB Gen capability. Use the following command to list the arbitration mailboxes with persisted capability of OABGen and database on which this mailbox is hosted: Get-Mailbox -Arbitration | where {$_.PersistedCapabilities -like "*oab*"} | ft name,database Step2: Identify the mailbox server where the database hosting organization mailbox is mounted Use following command to identify active copy of mailbox database: Get-MailboxDatabaseCopyStatus db1 The server where database status is “mounted” is the current OAB generation server. Change the OAB generation server There are two methods of changing the OAB generation server. Move mailbox Move the organization mailbox to a mailbox database on a server intended to be designated as OAB Generation server. Example: DB1 is a single copy database present on the server Exch1 and hosts the organization mailbox. DB2 is mailbox database present on Exch2. The following command can be used to move the organization mailbox to DB2 and make Exch2 the OAB generation server. Get-Mailbox -Arbitration -database db1| where {$_.PersistedCapabilities –like “*oab*”} | New-MoveRequest -TargetDatabase db2 This method is more suited for environments that have single copy of mailbox database hosting the Organization Mailbox. Activate the mailbox database on another server This method is suited for environments that have multiple copies of the mailbox database hosting Organization Mailbox. Example: DB1 hosts the Organization Mailbox and has copies on servers Exch1 and Exch2. DB1 is currently active on Exch1. The following command can be used to activate DB1 on Exch2 and therefore make it the OAB generation server: Move-ActiveMailboxDatabase DB1 -ActivateOnServer Exch2 Note: Review guidelines mentioned in “Placement of Organization Mailbox” below before changing the OAB Generation server. Creating a new Organization Mailbox Administrators can create additional Organization Mailboxes for fault tolerance or for serving users in a geographically disbursed Exchange deployment. Creating a new Organization Mailbox is a two step process: Step1: Create a new arbitration mailbox New-Mailbox -Arbitration -Name "OAB Seattle" -Database DB2Seattle -UserPrincipalName oabs@contoso.com –DisplayName “OAB Mailbox for Seattle” Step2: Enable OABGen capability Set-Mailbox -Arbitration oabs -OABGen $true -MaxSendSize 1GB Note: Review guidelines mentioned in “Placement of Organization Mailbox” below before creating additional organization mailboxes. Changing the OAB Generation Schedule The OAB Generation till Exchange Server 2010 was based on a “Schedule” set on OAB properties. You might see a “Schedule” defined when viewing properties of Exchange 2013 OAB. But, the Exchange Server 2013 OAB generation does not take place according to the “Schedule” defined on OAB properties: Instead, Exchange Server 2013 OAB Generation takes place according to OABGeneratorWorkCycle and OABGeneratorWorkCycleCheckpoint properties configured at the Mailbox Server. Example: The values in the above screenshot mean OAB is generated once every day. Which Mailbox Server processed the OAB download request? The Exchange Server 2013 CAS role proxies the OAB download request to an appropriate Mailbox role server. The CAS role maintains log of each request it handles in the log files, present in folder %ExchangeInstallPath%\Logging\HttpProxy\OAB\ These log files are an excellent tool to identify which mailbox server the CAS chose to serve the request. Information of some important fields from the log file: Field Description UrlStem Useful to identify the OAB being downloaded and also if this was a full download or incremental download AuthenticatedUser Name of the User requesting the OAB AnchorMailbox DN of Organization Mailbox identified as the closest to serve the OAB request ServerHostName CAS Server Name handling the request HttpStatus Status code for Proxy action ProxyAction Action CAS Server performed for the request, it will be mostly “Proxy” for Exchange 2013 OAB TargetServer Name of Mailbox role server to which request was proxied The log file can be imported in Excel for better readability. Example: Forcing the OAB Generation The Exchange Server 2013 OAB generation can be forced to start immediately by two methods. Method 1: Update-OfflineAddresBook Below command will force OAB generation of an OAB named "Default Offline Address Book" across all organization mailboxes. Update-OfflineAddressBook "default offline address book" Note: This command initiates an RPC request to each mailbox server hosting an active organization mailbox. Method 2: Restart the Mailbox Assistant service. The Microsoft Exchange Mailbox Assistant service on Mailbox Role is responsible for generating OAB. Restarting this service generates all OAB’s defined in the environment on a specific mailbox server, if it’s hosting an active organization mailbox. Placement of Organization Mailbox Exchange Server 2013 CAS role proxies the OAB download request to a “nearest” mailbox server hosting an active Organization Mailbox. It can proxy the request in round robin fashion if it finds more than one organization mailbox active in same AD site. Prior to CU5, this will result in frequent full OAB downloads and is therefore, not recommended. Hence, current guidance is to plan organization mailbox placement such that you will have one organization mailbox active in an AD site. This applies to creating a new organization mailbox as well as to creating copies of mailbox database that hosts an organization mailbox. Prior to CU5, customers should only deploy a single OAB generation mailbox per Exchange organization to prevent users from accessing different OAB generation mailboxes and requiring a full OAB download. With CU5 and later, customers can assign OABs to specific OAB generation mailboxes and not have to worry about accidentally triggering full OAB downloads due to accessing different OAB generation mailboxes. For more information, please see the article, OAB Improvements in Exchange 2013 Cumulative Update 5. Scenarios The following scenarios discuss a real life situation to further explain the new OAB management methods. Scenario 1: Create a new Organization Mailbox Contoso has Exchange Server 2013 Mailbox & CAS role servers deployed at Dallas and Seattle sites. John, the Exchange Admin for Contoso, analyzes the http proxy log files on CAS servers and finds the OAB download request for Seattle users is going to Dallas servers. On further investigation, John finds he has just one Organization Mailbox present in Dallas, hence OAB download requests of all the users are going to Dallas server. He decides to create a new Organization Mailbox at Seattle site with following commands: Step1: Create a new Arbitration Mailbox New-Mailbox -Arbitration -Name "OAB Seattle" -Database DB2Seattle -UserPrincipalName oabs@contoso.com –DisplayName “OAB Mailbox for Seattle” Step2: Enable the Arbitration Mailbox with OABGen capability Set-Mailbox -Arbitration oabs -OABGen $true -MaxSendSize 1GB Scenario 2: Customize OAB Generation Schedule Ben is an administrator of Exchange 2013 deployment at Tail Spin Toys. The default OAB generation schedule does not suit them and they want to generate OAB approximately every fourth hour of the day. Ben will use following command to change properties of the mailbox servers that will be hosting the Organization Mailbox. Set-MailboxServer Exch1 -OABGeneratorWorkCycle 01.00:00:00 -OABGeneratorWorkCycleCheckpoint 04:00:00 After a couple of days, John analyzes Event ID 17002 in application log and makes sure the OAB is generated every four hours. Hopefully, you find this post useful! Let us know your feedback below! Bhalchandra Atre Updates 5/15/14: Updated Placement of Organization Mailbox section to align with current guidance.The Preferred Architecture
During my session at the recent Microsoft Exchange Conference (MEC), I revealed Microsoft’s preferred architecture (PA) for Exchange Server 2013. The PA is the Exchange Engineering Team’s prescriptive approach to what we believe is the optimum deployment architecture for Exchange 2013, and one that is very similar to what we deploy in Office 365. While Exchange 2013 offers a wide variety of architectural choices for on-premises deployments, the architecture discussed below is our most scrutinized one ever. While there are other supported deployment architectures, other architectures are not recommended. The PA is designed with several business requirements in mind. For example, requirements that the architecture be able to: Include both high availability within the datacenter, and site resilience between datacenters Support multiple copies of each database, thereby allowing for quick activation Reduce the cost of the messaging infrastructure Increase availability by optimizing around failure domains and reducing complexity The specific prescriptive nature of the PA means of course that not every customer will be able to deploy it (for example, customers without multiple datacenters). And some of our customers have different business requirements or other needs, which necessitate an architecture different from that shown here. If you fall into those categories, and you want to deploy Exchange on-premises, there are still advantages to adhering as closely as possible to the PA where possible, and deviate only where your requirements widely differ. Alternatively, you can consider Office 365 where you can take advantage of the PA without having to deploy or manage servers. Before I delve into the PA, I think it is important that you understand a concept that is the cornerstone for this architecture – simplicity. Simplicity Failure happens. There is no technology that can change this. Disks, servers, racks, network appliances, cables, power substations, generators, operating systems, applications (like Exchange), drivers, and other services – there is simply no part of an IT services offering that is not subject to failure. One way to mitigate failure is to build in redundancy. Where one entity is likely to fail, two or more entities are used. This pattern can be observed in Web server arrays, disk arrays, and the like. But redundancy by itself can be prohibitively expensive (simple multiplication of cost). For example, the cost and complexity of the SAN based storage system that was at the heart of Exchange until the 2007 release, drove the Exchange Team to step up its investment in the storage stack and to evolve the Exchange application to integrate the important elements of storage directly into its architecture. We recognized that every SAN system would ultimately fail, and that implementing a highly redundant system using SAN technology would be cost-prohibitive. In response, Exchange has evolved from requiring expensive, scaled-up, high-performance SAN storage and related peripherals, to now being able to run on cheap, scaled-out servers with commodity, low-performance SAS/SATA drives in a JBOD configuration with commodity disk controllers. This architecture enables Exchange to be resilient to any storage related failure, while enabling you to deploy large mailboxes at a reasonable cost. By building the replication architecture into Exchange and optimizing Exchange for commodity storage, the failure mode is predictable from a storage perspective. This approach does not stop at the storage layer; redundant NICs, power supplies, etc., can also be removed from the server hardware. Whether it is a disk, controller, or motherboard that fails, the end result should be the same, another database copy is activated and takes over. The more complex the hardware or software architecture, the more unpredictable failure events can be. Managing failure at any scale is all about making recovery predictable, which drives the necessity to having predictable failure modes. Examples of complex redundancy are active/passive network appliance pairs, aggregation points on the network with complex routing configurations, network teaming, RAID, multiple fiber pathways, etc. Removing complex redundancy seems unintuitive on its face – how can removing redundancy increase availability? Moving away from complex redundancy models to a software-based redundancy model, creates a predictable failure mode. The PA removes complexity and redundancy where necessary to drive the architecture to a predictable recovery model: when a failure occurs, another copy of the affected database is activated. The PA is divided into four areas of focus: Namespace design Datacenter design Server design DAG design Namespace Design In the Namespace Planning and Load Balancing Principles articles, I outlined the various configuration choices that are available with Exchange 2013. From a namespace perspective, the choices are to either deploy a bound namespace (having a preference for the users to operate out of a specific datacenter) or an unbound namespace (having the users connect to any datacenter without preference). The recommended approach is to utilize the unbound model, deploying a single namespace per client protocol for the site resilient datacenter pair (where each datacenter is assumed to represent its own Active Directory site - see more details on that below). For example: autodiscover.contoso.com For HTTP clients: mail.contoso.com For IMAP clients: imap.contoso.com For SMTP clients: smtp.contoso.com Figure 1: Namespace Design Each namespace is load balanced across both datacenters in a configuration that does not leverage session affinity, resulting in fifty percent of traffic being proxied between datacenters. Traffic is equally distributed across the datacenters in the site resilient pair, via DNS round-robin, geo-DNS, or other similar solution you may have at your disposal. Though from our perspective, the simpler solution is the least complex and easier to manage, so our recommendation is to leverage DNS round-robin. In the event that you have multiple site resilient datacenter pairs in your environment, you will need to decide if you want to have a single worldwide namespace, or if you want to control the traffic to each specific datacenter pair by using regional namespaces. Ultimately your decision depends on your network topology and the associated cost with using an unbound model; for example, if you have datacenters located in North America and Europe, the network link between these regions might not only be costly, but it might also have high latency, which can introduce user pain and operational issues. In that case, it makes sense to deploy a bound model with a separate namespace for each region. Site Resilient Datacenter Pair Design To achieve a highly available and site resilient architecture, you must have two or more datacenters that are well-connected (ideally, you want a low round-trip network latency, otherwise replication and the client experience are adversely affected). In addition, the datacenters should be connected via redundant network paths supplied by different operating carriers. While we support stretching an Active Directory site across multiple datacenters, for the PA we recommend having each datacenter be its own Active Directory site. There are two reasons: Transport site resilience via Shadow Redundancy and Safety Net can only be achieved when the DAG has members located in more than one Active Directory site. Active Directory has published guidance that states that subnets should be placed in different Active Directory sites when the round trip latency is greater than 10ms between the subnets. Server Design In the PA, all servers are physical, multi-role servers. Physical hardware is deployed rather than virtualized hardware for two reasons: The servers are scaled to utilize eighty percent of resources during the worst-failure mode. Virtualization adds an additional layer of management and complexity, which introduces additional recovery modes that do not add value, as Exchange provides equivalent functionality out of the box. By deploying multi-role servers, the architecture is simplified as all servers have the same hardware, installation process, and configuration options. Consistency across servers also simplifies administration. Multi-role servers provide more efficient use of server resources by distributing the Client Access and Mailbox resources across a larger pool of servers. Client Access and Database Availability Group (DAG) resiliency is also increased, as there are more servers available for the load-balanced pool and for the DAG. Commodity server platforms (e.g., 2U, dual socket servers with no more than 24 processor cores and 96GB of memory, that hold 12 large form-factor drive bays within the server chassis) are use in the PA. Additional drive bays can be deployed per-server depending on the number of mailboxes, mailbox size, and the server’s scalability. Each server houses a single RAID1 disk pair for the operating system, Exchange binaries, protocol/client logs, and transport database. The rest of the storage is configured as JBOD, using large capacity 7.2K RPM serially attached SCSI (SAS) disks (while SATA disks are also available, the SAS equivalent provides better IO and a lower annualized failure rate). Bitlocker is used to encrypt each disk, thereby providing data encryption at rest and mitigating concerns around data theft via disk replacement. To ensure that the capacity and IO of each disk is used as efficiently as possible, four database copies are deployed per-disk. The normal run-time copy layout (calculated in the Exchange 2013 Server Role Requirements Calculator) ensures that there is no more than a single copy activated per-disk. Figure 2: Server Design At least one disk in the disk pool is reserved as a hot spare. AutoReseed is enabled and quickly restores database redundancy after a disk failure by activating the hot spare and initiating database copy reseeds. Database Availability Group Design Within each site resilient datacenter pair you will have one or more DAGs. DAG Configuration As with the namespace model, each DAG within the site resilient datacenter pair operates in an unbound model with active copies distributed equally across all servers in the DAG. This model provides two benefits: Ensures that each DAG member’s full stack of services is being validated (client connectivity, replication pipeline, transport, etc.). Distributes the load across as many servers as possible during a failure scenario, thereby only incrementally increasing resource utilization across the remaining members within the DAG. Each datacenter is symmetrical, with an equal number of member servers within a DAG residing in each datacenter. This means that each DAG contains an even number of servers and uses a witness server for quorum arbitration. The DAG is the fundamental building block in Exchange 2013. With respect to DAG size, a larger DAG provides more redundancy and resources. Within the PA, the goal is to deploy larger DAGs (typically starting out with an eight member DAG and increasing the number of servers as required to meet your requirements) and only create new DAGs when scalability introduces concerns over the existing database copy layout. DAG Network Design Since the introduction of continuous replication in Exchange 2007, Exchange has recommended multiple replication networks for separating client traffic from replication traffic. Deploying two networks allows you to isolate certain traffic along different network pathways and ensure that during certain events (e.g., reseed events) the network interface is not saturated (which is an issue with 100Mb, and to a certain extent, 1Gb interfaces). However, for most customers, having two networks operating in this manner was only a logical separation, as the same copper fabric was used by both networks in the underlying network architecture. With 10Gb networks becoming the standard, the PA moves away from the previous guidance of separating client traffic from replication traffic. A single network interface is all that is needed because ultimately our goal is to achieve a standard recovery model despite the failure - whether a server failure occurs or a network failure occurs, the result is the same, a database copy is activated on another server within the DAG. This architectural change simplifies the network stack, and obviates the need to eliminate heartbeat cross-talk. Witness Server Placement Ultimately, the placement of the witness server determines whether the architecture can provide automatic datacenter failover capabilities or whether it will require a manual activation to enable service in the event of a site failure. If your organization has a third location with a network infrastructure that is isolated from network failures that affect the site resilient datacenter pair in which the DAG is deployed, then the recommendation is to deploy the DAG’s witness server in that third location. This configuration gives the DAG the ability to automatically failover databases to the other datacenter in response to a datacenter-level failure event, regardless of which datacenter has the outage. Figure 3: DAG (Three Datacenter) Design If your organization does not have a third location, then place the witness server in one of the datacenters within the site resilient datacenter pair. If you have multiple DAGs within the site resilient datacenter pair, then place the witness server for all DAGs in the same datacenter (typically the datacenter where the majority of the users are physically located). Also, make sure the Primary Active Manager (PAM) for each DAG is also located in the same datacenter. Data Resiliency Data resiliency is achieved by deploying multiple database copies. In the PA, database copies are distributed across the site resilient datacenter pair, thereby ensuring that mailbox data is protected from software, hardware and even datacenter failures. Each database has four copies, with two copies in each datacenter, which means at a minimum, the PA requires four servers. Out of these four copies, three of them are configured as highly available. The fourth copy (the copy with the highest Activation Preference) is configured as a lagged database copy. Due to the server design, each copy of a database is isolated from its other copies, thereby reducing failure domains and increasing the overall availability of the solution as discussed in DAG: Beyond the “A”. The purpose of the lagged database copy is to provide a recovery mechanism for the rare event of system-wide, catastrophic logical corruption. It is not intended for individual mailbox recovery or mailbox item recovery. The lagged database copy is configured with a seven day ReplayLagTime. In addition, the Replay Lag Manager is also enabled to provide dynamic log file play down for lagged copies. This feature ensures that the lagged database copy can be automatically played down and made highly available in the following scenarios: When a low disk space threshold is reached When the lagged copy has physical corruption and needs to be page patched When there are fewer than three available healthy copies (active or passive) for more than 24 hours By using the lagged database copy in this manner, it is important to understand that the lagged database copy is not a guaranteed point-in-time backup. The lagged database copy will have an availability threshold, typically around 90%, due to periods where the disk containing a lagged copy is lost due to disk failure, the lagged copy becoming an HA copy (due to automatic play down), as well as, the periods where the lagged database copy is re-building the replay queue. To protect against accidental (or malicious) item deletion, Single Item Recovery or In-Place Hold technologies are used, and the Deleted Item Retention window is set to a value that meets or exceeds any defined item-level recovery SLA. With all of these technologies in play, traditional backups are unnecessary; as a result, the PA leverages Exchange Native Data Protection. Summary The PA takes advantage of the changes made in Exchange 2013 to simplify your Exchange deployment, without decreasing the availability or the resiliency of the deployment. And in some scenarios, when compared to previous generations, the PA increases availability and resiliency of your deployment. Ross Smith IV Principal Program Manager Office 365 Customer Experience
