Additional Endpoints Required for AAD Authentication and CRL Checks for Azure SQL DB
You may have attempts to connect to Azure SQL Database with an Azure Active Directory (AAD) account that are failing with a timeout error, but SQL Authentication works as expected. Alternatively you could be encountering generic connection errors with the inner exception being ‘Revocation of the SSL certificate failed’. If the following workarounds are not sufficient, you may have to whitelist specific endpoints on your Firewalls or network infrastructure: Disabling the Revocation of the SSL Certificate Check: Revocation of the SSL certificate failed for AAD authentication - Microsoft Tech Community Allowing all SSL traffic from that server on their firewall An example of the ‘Revocation of the SSL certificate failed’ error in SQL Server Management Studio (SSMS): You can take a network trace in order to see where traffic is being blocked, or to grab the certificate that is being passed back. Having the certificate will allow you to examine the CRL endpoints listed in the certificate itself. Instead of taking a network trace, you may want to watch blocked traffic on your Firewall and whitelist trusted endpoints that appear in order to expedite troubleshooting. You can test connectivity to ports via PowerShell using, for example, “tnc login.windows.net -port 443”. If you have an ADFS setup, then to authenticate you will need to whitelist your ADFS endpoint on port 443. If you have multiple ADFS endpoints you will need to whitelist the one that your DNS server is resolving you to. This is a non-exhaustive list of endpoints that may be required depending on the authentication type. Additional endpoints may be required to communicate with Active Directory Federation Services (ADFS), or depending on your networking path and if you are using a public Certification Authority (CA), endpoints for whoever has issued your certificate for ADFS. Please note not all Firewalls can be configured to accept wildcards, and while the below list has as many explicitly defined URLs as possible, you may need to see what traffic is being blocked on the Firewall to get definite URLs for those not fully defined here. This is also how you can determine if something not on this list is being blocked and is required for your particular networking setup (perhaps the ADFS endpoint your machine is reaching out to is not the one you expect, etc). URL Port Description mscrl.microsoft.com HTTP/80 Used to download CRL lists. *.verisign.com HTTP/80 Used to download CRL lists. *.entrust.net HTTP/80 Used to download CRL lists for MFA. *.management.core.windows.net (Azure Storage) *.graph.windows.net (Azure AD Graph) HTTPS/443 Used for the various Azure services secure.aadcdn.microsoftonline-p.com HTTPS/443 Used for MFA. *.microsoftonline.com HTTPS/443 Used to configure your Azure AD directory and import/export data. login.microsoftonline.us HTTPS/443 Used by US Gov for AD Login. login.microsoftonline.com HTTPS/443 Used by Public cloud for AD login for MFA. login.windows.net HTTPS/443 Used by Public cloud for AD login for Password and Integrated. http://crl.microsoft.com HTTP/80 Used to verify certificates. http://crl3.digicert.com HTTP/80 Used to verify certificates. http://crl4.digicert.com HTTP/80 Used to verify certificates. http://ocsp.digicert.com HTTP/80 Used to verify certificates. http://www.d-trust.net HTTP/80 Used to verify certificates. http://root-c3-ca2-2009.ocsp.d-trust.net HTTP/80 Used to verify certificates. http://crl.microsoft.com HTTP/80 Used to verify certificates. http://oneocsp.microsoft.com HTTP/80 Used to verify certificates. http://ocsp.msocsp.com HTTP/80 Used to verify certificates. http://www.microsoft.com/pkiops HTTP/80 Used to verify certificates. cacerts.digicert.com HTTP/80 Used to verify certificates. ctldl.windowsupdate.com HTTP/80 Used to verify certificates. References Azure Active Directory certificate authorities | Microsoft Docs Azure TLS Certificate Changes | Microsoft Docs Azure AD Connect: Troubleshoot Azure AD connectivity issues | Microsoft Docs Revocation of the SSL certificate failed for AAD authentication - Microsoft Tech Community Microsoft 365 endpoints - Microsoft 365 Enterprise | Microsoft DocsLesson Learned #383: Loading multiple extended file using sys.fn_xe_file_target_read_file
In today's technologically advanced world, data plays a crucial role in driving decision-making processes and gaining valuable insights. One of the popular methods for capturing and analyzing data in Microsoft SQL Server is through Extended Events (XE). XE allows administrators to collect information about various events occurring within the SQL Server environment. However, managing and loading multiple extended event files can be a challenging task. In this article, we will explore an effective solution using the sys.fn_xe_file_target_read_file function to load multiple extended event files seamlessly.Azure SQL DB Private Link / Private Endpoint - Connectivity Troubleshooting
In the articleAzure SQL DB Connectivity Troubleshootingwe have explored regular connectivity troubleshooting to Azure SQL DB, on this one we will explore connectivity troubleshooting using Private Link In this article we are going to explore What is the Private Endpoint for Azure DB? Creation of Private Endpoint Azure VM > Private Link OnPrem VM > VPN (P2S) > Private Link (Hosts File) OnPrem VM > VPN (P2S) > Private Link (Custom DNS) Azure Function > VNET integration > Private Endpoint Failover Groups with Private Link 1 - What is the Private Endpoint for Azure DB? Azure Private Link enables you to access Azure PaaS Services (for example, Azure Storage and SQL Database) and Azure hosted customer-owned/partner services over aprivate endpointin your virtual network. Traffic between your virtual network and the service travels the Microsoft backbone network. Exposing your service to the public internet is no longer necessary Some important information Private Link service can be accessed from approved private endpoints in the same region. The private endpoint can be reached from the same virtual network, regionally peered VNets, globally peered VNets and on premises using private VPN or ExpressRoute connections. When creating a Private Link Service, a network interface is created for the lifecycle of the resource. This interface is not manageable by the customer. The Private Link Service must be deployed in the same region as the virtual network. A single Private Link Service can be accessed from multiple Private Endpoints belonging to different VNets, subscriptions and/or Active Directory tenants. The connection is established through a connection workflow. In the image, below we can see how the connection using private endpoint works. And as mentioned on the other articleAzure SQL DB Connectivity Troubleshootingthe Azure SQL DB clients by default will all go to the Shared public IP of the regional gateway. With the private endpoint you can close this public path and users can only connect from private endpoint. If you have multiple Azure VNETs you will need to use VNET peering or VNET VPN between two Azure VNETs, or P2S,S2S or Express Route to connect your onprem to Azure Network 2 - Creation of Private Endpoint To create a Private endpoint just follow up the procedure documented athttps://docs.microsoft.com/en-us/azure/private-link/create-private-endpoint-portal You may also want to close all public network access to make sure all connection must flow from Private Endpoint. Just need to go to Azure SQL DB instance and "Firewall and Virtual Networks" and Deny public network access. Find below the procedure I've used to create a Private Endpoint Just need to go to "Private Endpoint Connections" and then add a Private endpoint Select the region that should be the same as the VNET region as mentioned above. Select the resource type "Microsoft.Sql/servers" for Azure SQL DB instance Select the Azure SQL DB instance you want to connect Select the VNET / Subnet. Notice also that during the creation you can already create a private DNS zone, that will work for Azure resources that uses the Azure DNS. We will talk more about that when doing the tests 3 - Azure VM > Private Endpoint From an Azure VM deployed to same VNET, if we test command below on command prompt before you create the Private Endpoint. nslookup fonsecanet-westeu.database.windows.net You will get result like below that shows that this server is using public gateway IP:40.68.37.158. So NOT using any private IP Server: UnKnown Address: 168.63.129.16 Non-authoritative answer: Name: westeurope1-a.control.database.windows.net Address: 40.68.37.158 Aliases: fonsecanet-westeu.database.windows.net After you create the Private Endpoint using the same command above you are expected to see the results below Server: UnKnown Address: 168.63.129.16 Non-authoritative answer: Name: fonsecanet-westeu.privatelink.database.windows.net Address: 10.0.1.4 Aliases: fonsecanet-westeu.database.windows.net Be sure also to open outbound communication from Azure VM VNET to Private Endpoint on Local Firewall, Corporate Firewall, or Azure NSGs. For this test I've opened to allow all communication inside VNET. *Currently(Status on 2020-04-06) redirect is not supported, so only needed 1433 port You must use the FQDN to connect to Azure SQL DB as documented athttps://docs.microsoft.com/en-us/azure/sql-database/sql-database-private-endpoint-overview#check-connectivity-using-sql-server-management-studio-ssms Use theFully Qualified Domain Name (FQDN)of the server in connection strings for your clients. Any login attempts made directly to the IP address shall fail. This behavior is by design, since private endpoint routes traffic to the SQL Gateway in the region and the FQDN needs to be specified for logins to succeed. You can also check if connection is correct using TSQL below. And we will see the client IP is the private IP assigned to Azure VM. SELECT client_net_address FROM sys.dm_exec_connections where session_id = @@SPID You must use the FQDN to connect to Azure SQL DB. Azure SQL DB gateway use the name to route correctly your connection to the SQL host, when information is not provided it will fail If you try to connect using private endpoint IP you are going to get error like below =================================== Cannot connect to 10.0.1.4. =================================== A connection was successfully established with the server, but then an error occurred during the login process. (provider: SSL Provider, error: 0 - The target principal name is incorrect.) (.Net SqlClient Data Provider) ------------------------------ Server Name: 10.0.1.4 Error Number: -2146893022 Severity: 20 State: 0 You should also NOT use DB.privatelink.database.windows.net =================================== Cannot connect to fonsecanet-westeu.privatelink.database.windows.net. =================================== A connection was successfully established with the server, but then an error occurred during the login process. (provider: SSL Provider, error: 0 - The target principal name is incorrect.) (.Net SqlClient Data Provider) ------------------------------ Server Name: fonsecanet-westeu.privatelink.database.windows.net Error Number: -2146893022 Severity: 20 State: 0 4 - OnPrem VM > VPN (P2S) > Private Link (Hosts File) You can use some template like below to create the VPN Point to Site https://docs.microsoft.com/en-us/azure/sql-database/sql-database-managed-instance-configure-p2s https://docs.microsoft.com/en-us/azure/vpn-gateway/vpn-gateway-howto-point-to-site-resource-manager-portal After creating the VPN, downloading and installing the VPN client and connecting to it If I check name resolution nslookup fonsecanet-westeu.database.windows.net We can see that it is still using Microsoft internal Corporate DNS where this VM is located Server: XXXXXXXXXXX.corp.microsoft.com Address: 10.221.xx.xx Non-authoritative answer: Name: westeurope1-a.control.database.windows.net Address: 40.68.37.158 Aliases: fonsecanet-westeu.database.windows.net fonsecanet-westeu.privatelink.database.windows.net For this scenario you will need to use your corporate DNS to have the name resolution https://docs.microsoft.com/en-us/azure/private-link/private-endpoint-overview#dns-configuration When connecting to a private link resource using a fully qualified domain name (FQDN) as part of the connection string, it's important to correctly configure your DNS settings to resolve to the allocated private IP address. Existing Azure services might already have a DNS configuration to use when connecting over a public endpoint. This needs to be overridden to connect using your private endpoint. The network interface associated with the private endpoint contains the complete set of information required to configure your DNS, including FQDN and private IP addresses allocated for a given private link resource. You can use the following options to configure your DNS settings for private endpoints: Use the Host file (only recommended for testing). You can use the host file on a virtual machine to override the DNS. Use a private DNS zone. You can use private DNS zones to override the DNS resolution for a given private endpoint. A private DNS zone can be linked to your virtual network to resolve specific domains. Use your custom DNS server. You can use your own DNS server to override the DNS resolution for a given private link resource. If yourDNS serveris hosted on a virtual network, you can create a DNS forwarding rule to use a private DNS zone to simplify the configuration for all private link resources. Important It's not recommended to override a zone that is actively in use to resolve public endpoints. Connections to resources won't be able to resolve correctly without DNS forwarding to the public DNS. To avoid issues, create a different domain name or follow the suggested name for each service below. Private Link resource type Subresource Zone name SQL DB (Microsoft.Sql/servers) Sql Server (sqlServer) privatelink.database.windows.net Azure will create a canonical name DNS record (CNAME) on the public DNS to redirect the resolution to the suggested domain names. You'll be able to override the resolution with the private IP address of your private endpoints. Your applications don't need to change the connection URL. When attempting to resolve using a public DNS, the DNS server will now resolve to your private endpoints. The process does not impact your applications. For this test will use HOST file solution And we are able to connect fine. And as before you will be able to check you get the VPN ip range using TSQL below SELECT client_net_address FROM sys.dm_exec_connections where session_id = @@SPID 5 - OnPrem VM > VPN (P2S) > Private Link (Custom DNS) If you do not want to use local hosts file as mentioned above you can add Azure DNS (168.63.129.16) as a forwarder on your custom DNS For more information about more complex DNS relationships follow up the official documentationhttps://docs.microsoft.com/en-us/azure/private-link/private-endpoint-dns On Azure Virtual Network settings I've replaced default Azure DNS with your custom DNS (On my tests 10.0.0.5). You can also add168.63.129.16 (Azure DNS) as secondary DNS just in case 1st is off If your client lives in Azure, the DNS on VM can be a forwarder to Azure DNS - Go to DNS > Domain > Properties > Forwarders - AddAzure DNS (168.63.129.16) Do not forget to add virtual network link from Private Zone to the VNET where your Azure VM with DNS lives. If you are have onprem DNS you may need a Conditional forwarder Go to DNS > Domain > Conditional Forwarders > New DNS Domain should be database.windows.net. DO NOT USE privatelink.database.windows.net And you can check if name resolution works fine nslookup fonsecanet-westeu.database.windows.net Server: fonsecanetad.internal.cloudapp.net Address: 10.0.0.5 Non-authoritative answer: Name: fonsecanet-westeu.privatelink.database.windows.net Address: 10.0.1.4 Aliases: fonsecanet-westeu.database.windows.net If do not want to use forwarder you can also create aforward lookup zone and added manually the hostto match the FQDN 6 - Azure Function > VNET integration > Private Endpoint To make Azure Function to connect to private endpoint you will need to use VNET integration https://docs.microsoft.com/en-us/azure/azure-functions/functions-create-vnet https://docs.microsoft.com/en-us/azure/app-service/web-sites-integrate-with-vnet *Status on (2020-04-27) There was some limitation on webapp + private DBS that are now gone and just need to set some configurationsas documented athttps://docs.microsoft.com/en-us/azure/app-service/web-sites-integrate-with-vnet#azure-dns-private-zones After your app integrates with your VNet, it uses the same DNS server that your VNet is configured with. By default, your app won't work with Azure DNS Private Zones. To work with Azure DNS Private Zones you need to add the following app settings: WEBSITE_DNS_SERVER with value 168.63.129.16 WEBSITE_VNET_ROUTE_ALL with value 1 These settings will send all of your outbound calls from your app into your VNet in addition to enabling your app to use Azure DNS private zones. And I've also created a sample Azure Function app that accept the connection string as parameter and was able to connect fine You can check the source code athttps://github.com/FonsecaSergio/AzureFunctionAppTestConnectivity 7 - Failover Groups with Private Link For this scenario I will just reference link from Product Group articlehttps://techcommunity.microsoft.com/t5/azure-sql-database/using-failover-groups-with-private-link-for-azure-sql-database/ba-p/1272902 Be sure to config private zone network link to both networks https://docs.microsoft.com/en-us/azure/private-link/private-endpoint-dns#virtual-network-workloads-without-custom-dns-server This model can be extended to multiple peered virtual networks that are associated to the same private endpoint. This can be done byadding new virtual network linksto the private DNS zone for all peered virtual networks. Result for my tests C:\Users\FonsecaSergio>nslookup SERVER1.database.windows.net Server: UnKnown Address: 168.63.129.16 Non-authoritative answer: Name: SERVER1.privatelink.database.windows.net Address: 12.1.1.6 Aliases: SERVER1.database.windows.net C:\Users\FonsecaSergio>nslookup SERVER2-westus.database.windows.net Server: UnKnown Address: 168.63.129.16 Non-authoritative answer: Name: SERVER2-westus.privatelink.database.windows.net Address: 11.0.1.4 Aliases: SERVER2-westus.database.windows.net C:\Users\FonsecaSergio>nslookup FAILOVERGROUP.database.windows.net Server: UnKnown Address: 168.63.129.16 Non-authoritative answer: Name: SERVER1.privatelink.database.windows.net Address: 12.1.1.6 Aliases: FAILOVERGROUP.database.windows.net SERVER1.database.windows.net ForDNS on more complex environments, please follow up other scenarios as mentioned at https://docs.microsoft.com/en-us/azure/private-link/private-endpoint-dns REF and LINKS https://docs.microsoft.com/en-us/azure/private-link/private-link-service-overview https://docs.microsoft.com/en-us/azure/private-link/private-endpoint-overview https://docs.microsoft.com/en-us/azure/sql-database/sql-database-private-endpoint-overview https://docs.microsoft.com/en-us/azure/private-link/ https://docs.microsoft.com/en-us/azure/app-service/web-sites-integrate-with-vnet#enable-vnet-integration https://channel9.msdn.com/Shows/Data-Exposed/Private-Link-for-Azure-SQL-Database-Part-1?term=Private%20Link%20for%20Azure%20SQL%20Database&lang-en=true https://channel9.msdn.com/Shows/Data-Exposed/Private-Link-for-Azure-SQL-Database-Part-2?term=Private%20Link%20for%20Azure%20SQL%20Database&lang-en=trueTesting connectivity against a Managed Instance using a CNAME
As documented here.We can change the SQL Managed Instance default DNS zone".database.windows.net"to any of your choice. However, the instance name part of the FQDN is mandatory. Whether you are connecting through a public or private endpoint, the virtual cluster manages the connection and then either proxies or redirects it to the appropriate SQL MI resident within the same cluster based on the connection type configured. The virtual cluster utilizes the hostname part of the FQDN in the connection string to lookup for the MI. If the instance name doesn't match an existing one, the connection attempt will fail. For instance, if the FQDN issqlmi01.a1b2c3d4.database.windows.net and the CNAME isdb01.contoso.com it will not work A workaround is to create a 'user@sqlmi01' login on sqlmi01 and pass it in the connection string using SQL Server authentication. This explicitly tells the virtual cluster to disregard the hostname in the FQDN and look up a managed instance called sqlmi01. Another option is to use the same hostname in the CNAME record, sosqlmi01.contoso.com would work. Although this won't suit multiple SQL MIs because SQL MI names are globally unique. One thing to note is that when using option 2 from the section above, is that all encrypted connections will fail by default. Reason being that the server-side certificate will not match with the FQDN provided in the connection string. There are a few ways around this. The first one is to use set the propertytrustServerCertificate to true. Although we should mention that this is not a recommended setting as that option is inherently insecure. Recently, there weresome new releasesand announcementsfor ODBC and OLEDB drivers, I was curious enough to set a test with a CNAME pointing to a managed instance public endpoint and perform some tests with the new settings of said drivers. Specifically, the hostNameInCertificatesetting, that could help us with the problem described in option 2 above. As explained on the articles linked above the new releases of ODBC (18) and OLEDB (19) have a few breaking changes, that could impact the connectivity for yourparticular scenario. Below are the results of my tests using SSMS (.Net SqlClient), ODBC (17 and 18) and OLEDB (18 and 19). Test # Tool Version Authentication EncryptConnection Encrypt Value Trust Server Certificate Hostname in Certificate Result 1 SSMS (.Net SqlClient) 18.11.1 SQL FALSE N/A FALSE N/A Success 2 SSMS (.Net SqlClient) 18.11.1 SQL TRUE N/A FALSE N/A Failure 3 SSMS (.Net SqlClient) 18.11.1 SQL TRUE N/A TRUE N/A Success 4 SSMS (.Net SqlClient) 18.11.1 AAD FALSE N/A FALSE N/A Failure 5 SSMS (.Net SqlClient) 18.11.1 AAD TRUE N/A FALSE N/A Failure 6 SSMS (.Net SqlClient) 18.11.1 AAD TRUE N/A TRUE N/A Success 7 ODBC 17.9.1.1 SQL FALSE N/A FALSE N/A Success 8 ODBC 17.9.1.1 SQL TRUE N/A FALSE N/A Failure 9 ODBC 17.9.1.1 SQL TRUE N/A TRUE N/A Success 10 ODBC 17.9.1.1 AAD FALSE N/A FALSE N/A Success 11 ODBC 17.9.1.1 AAD TRUE N/A FALSE N/A Failure 12 ODBC 17.9.1.1 AAD TRUE N/A TRUE N/A Success 13 OLEDB 18.6.3 SQL FALSE N/A FALSE N/A Success 14 OLEDB 18.6.3 SQL TRUE N/A FALSE N/A Failure 15 OLEDB 18.6.3 SQL TRUE N/A TRUE N/A Success 16 OLEDB 18.6.3 AAD FALSE N/A FALSE N/A Failure 17 OLEDB 18.6.3 AAD TRUE N/A FALSE N/A Failure 18 OLEDB 18.6.3 AAD TRUE N/A TRUE N/A Failure 19 ODBC 18.0.1.1 SQL FALSE Optional FALSE Blank Failure 20 ODBC 18.0.1.1 SQL FALSE Optional FALSE Set Success 21 ODBC 18.0.1.1 SQL FALSE Optional TRUE Blank Success 22 ODBC 18.0.1.1 SQL TRUE Mandatory FALSE Blank Failure 23 ODBC 18.0.1.1 SQL TRUE Mandatory FALSE Set Success 24 ODBC 18.0.1.1 SQL TRUE Mandatory TRUE Blank Success 25 ODBC 18.0.1.1 SQL TRUE Strict N/A Blank Failure 26 ODBC 18.0.1.1 SQL TRUE Strict N/A Set Failure 27 ODBC 18.0.1.1 AAD FALSE Optional FALSE Blank Failure 28 ODBC 18.0.1.1 AAD FALSE Optional FALSE Set Success 29 ODBC 18.0.1.1 AAD FALSE Optional TRUE Blank Success 30 ODBC 18.0.1.1 AAD TRUE Mandatory FALSE Blank Failure 31 ODBC 18.0.1.1 AAD TRUE Mandatory FALSE Set Success 32 ODBC 18.0.1.1 AAD TRUE Mandatory TRUE Blank Success 33 ODBC 18.0.1.1 AAD TRUE Strict N/A Blank Failure 34 ODBC 18.0.1.1 AAD TRUE Strict N/A Set Failure 35 OLEDB 19.0.0 SQL FALSE Optional FALSE Blank Failure 36 OLEDB 19.0.0 SQL FALSE Optional FALSE Set Success 37 OLEDB 19.0.0 SQL FALSE Optional TRUE Blank Failure 38 OLEDB 19.0.0 SQL TRUE Mandatory FALSE Blank Failure 39 OLEDB 19.0.0 SQL TRUE Mandatory FALSE Set Success 40 OLEDB 19.0.0 SQL TRUE Mandatory TRUE Blank Failure 41 OLEDB 19.0.0 SQL TRUE Strict N/A Blank Failure 42 OLEDB 19.0.0 SQL TRUE Strict N/A Set Failure 43 OLEDB 19.0.0 AAD FALSE Optional FALSE Blank Failure 44 OLEDB 19.0.0 AAD FALSE Optional FALSE Set Success 45 OLEDB 19.0.0 AAD FALSE Optional TRUE Blank Failure 46 OLEDB 19.0.0 AAD TRUE Mandatory FALSE Blank Failure 47 OLEDB 19.0.0 AAD TRUE Mandatory FALSE Set Success 48 OLEDB 19.0.0 AAD TRUE Mandatory TRUE Blank Failure 49 OLEDB 19.0.0 AAD TRUE Strict N/A Blank Failure 50 OLEDB 19.0.0 AAD TRUE Strict N/A Set Failure As we can see there might be a difference on the result depending on the driver, the settings and the version used. Whenever possible try updating and testing your drivers to ensure the stability of your connections Cheers!Auto Scale - Azure SQL elastic pools
We have received a few inquiries and service requests regarding having an automatic scale for Azure SQL elastic pools and this blog was written based on the previous great blog article by our colleague Julio Calderón (How-to auto-scale Azure SQL Databases - Microsoft Community Hub) which explained how to perform auto scale for Azure SQL database. This blog article will be a continuation of the previous one to cover the Azure SQL elastic pool.Lesson Learned #460: DataIO vs Buffer Pool
In the past week, we have dedicated our efforts to a service request where our customer asked questions: Whether DataIO signifies the utilization of memory by the Buffer Pool. The rationale behind Azure SQL Database not releasing the memory allocated in the buffer pool. In the following discussion, I would like to share with you the details of this explanation.
