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DNS Suffix vs. Active Directory Domain for HPC cluster

DNS Suffix vs. Active Directory Domain for HPC cluster

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A few months ago, I was asked a question about how to assign a connection specific DNS Suffix to a NIC which was different from the Active Directory Domain.  For example, the AD Domain was contoso.com, but they wanted to be able to assign a DNS suffix of cluster.contoso.com.  If the Fully Qualified Domain Name (FQDN) of cluster.contoso.com was specified as a DHCP scope option (015 DNS Domain Name), then the installation would fail when the nodes attempted to join an Active Directory Domain that did not exist. 

This scenario would only arise for clusters which are configured with network topology 2 or 4, where all the compute nodes have a connection to the enterprise LAN as well as to the private one.  Otherwise, this would not be an issue, because the compute nodes would only be connected to the private network and would not be accessable from the rest of the enterprise and therefore would not have DNS entries.

After some searching, I determined that a good work around would be to add a new domain to the contoso.com DNS Forward Lookup Zone.  The steps to implement this solution are as follows:

  1. Specify cluster.contoso.com as the 015 DNS Domain Name scope option for the DHCP server which manages the scope that includes the NIC's on the cluster nodes which are attached to the enterprise network.
  2. Install the head node.  Before joining the AD Domain, verify the Connection-specific DNS suffix for the enterprice NIC by running the ipconfig command. 
  3. Join the head node to the contoso.com AD Domain.  Install the HPC Pack and follow the standard proceedure for installing the compute nodes from bare metal.  When this process completes, the nodes will all belong to the contoso.com AD Domain, and the DNS Host(A) records for all the nodes will indicate the FQDN to be <hostname>.contoso.com.  However, the ipconfig command will show that the Connection-specific DNS suffix for the enterprise NIC's is cluster.contoso.com.
  4. Add a New Domain to the contoso.com DNS Forward Lookup zone.


  5. Name the New Domain "cluster".  Then add New Alias (CNAME) records to this domain for each of the nodes in the cluster which equate the <hostname>.cluster.contoso.com FQDN to the target <hostname>.contoso.com FQDN.

 

Please let me know if this information was helpful to you.  

Comments
  • Thanks for this great information.

    I also was wondering whether the same procedure could be followed for the wireless cards as well.

    Please let me know.

  • It should.  Since the DNS suffix is connection specific, all you should need to do is update the 015 DNS Domain Name scope option for the DHCP server which manages the scope that includes the Wireless NIC's on the cluster.  

  • In an earlier post , I described an approach for resolving names when the connection specific DNS suffix

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