How to Configure an Alias for a Clustered SMB Share with Windows Server 2012

[Elden Christensen]

First published on MSDN on Apr 08, 2012
Starting with Windows Server 2008, SMB file shares on a Failover Cluster are scoped so that they are only accessible by valid UNC paths associated with the network name they are bound to.  See this blog for more information:
http://blogs.technet.com/b/askcore/archive/2009/01/09/file-share-scoping-in-windows-server-2008-...

File Share Scoping delivered improved functionality that solved a number of issues, but introduced some side effects.  Namely that you could no longer connect to SMB shares on a Failover Cluster by the IP address or in some scenarios you may wish to connect by a name other than the name associated with the cluster Network Name resource.  For example, using DNS CNAME records to alias server names.

Now with Windows Server 2012 there is greater flexibility in connecting to clustered SMB file shares, where you can connect with the associated IP address and define aliases for the clustered shares to be available with.  This can be helpful when dealing with applications that are hardcoded to specific names or directly to IP addresses.

Connecting using an IP Address:

Cluster Network Name resources have a dependency on one or more IP Address resources.  Aliases will be automatically created in the cluster so that connecting using one of the IP Addresses will associate it with the network name that depends on it.   You will be able to connect specifying the IP address with no additional configuration steps in the following format:
\\10.10.10.10\Share

Note:  File based storage with the new Windows Server 2012 Scale-out File Server for Application Data feature does not support connecting via IP address, as Scale-Out File Server does not use cluster IP Address resources with those types of configurations.  For more information on Scale-Out File Server, see this document .

Connecting using an Alias:

It is now possible to configure scoped SMB shares on a Clustered File Server to listen for aliases with Windows Server 2012.  This is a two-step process involving both DNS and Failover Cluster configuration.  The following steps outline how to configure an alias with an example name of “AliasName” for the Network Name resource called “MyClusterName” that is part of a highly available File Server role.
Configure DNS:
1.  On the DNS server configure a CNAME record for AliasName.  See this KB article for details: http://support.microsoft.com/kb/168322

Alternatively, provide some other name resolution mechanism that allows the client to resolve AliasName
Configure Cluster:
2.  On the Cluster open an elevated Windows PowerShell® prompt

3.  View the currently configured aliases on the MyClusterName Network Name resource:
Get-ClusterResource "MyClusterName" | Get-ClusterParameter Aliases

4.  Add a new alias to the MyClusterName Network Name resource with the name of “AliasName”, type the following:
Get-ClusterResource "MyClusterName" | Set-ClusterParameter Aliases AliasName





Note:  For the setting to take effect it requires recycling (taking Offline then Online) the cluster Network Name resource.  The new alias will now appear for the Network Name resource.



5.  Connect to a share by specifying the alias
\\AliasName\Share

Considerations:

Connecting to an SMB share by IP address, or an alias, on a clustered or stand-alone server does not support Kerberos authentication.  Connections will be negotiated with NTLM.  While connecting with aliases does bring flexibility, the security trade-offs should be taken into consideration.

Multiple aliases can also be configured for an individual Network Name resource.  This can be configured by typing the following:
Get-ClusterResource "MyClusterName" | Set-ClusterParameter Aliases "Alias1,Alias2"
Thanks!
Elden Christensen
Principal Program Manager Lead
Clustering & High-Availability
Microsoft