Windows

Adding multiple NetBIOS names for Windows servers

Sometimes a single server has to serve multiple NetBIOS names. Rick Vanover shares this trick to having one server work double duty in the NetBIOS department.

A server's NetBIOS name is what we still use as the single most consistent identifier for file sharing resources. Each time we access a file share resource in the \\server\share format, we are accessing the server's NetBIOS name. You could access file resources in the \\server.fullyqualified.domain\share format, but I haven't known many admins to go that route.

For the NetBIOS name of a server, this is currently set as a single value within Server Manager; but a Windows server is very capable of serving multiple NetBIOS names. Look no further than clustering services to host a computer name for a clustered service or resource; this is the most frequent implementation of a multiple NetBIOS names being served. In the case of clustering, the clustered resource computer name is usually different than the member servers, so it can easily be moved between each server.

The best reason to manually configure multiple NetBIOS names on a single server is to move something from a cluster to a standalone server. A good example is migrating a file server cluster that has multiple computer name resources to a single server that is a virtual machine. In most situations, clustering services are only used to provide availability; in today's infrastructure, that availability can easily be delivered with virtual machines. You may be able to step down from Windows Enterprise Edition to Standard Edition, as clustering services are not required at this point; this would also reduce your Windows costs.

You can add another NetBIOS name in the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanServer\Parameters section of the Windows registry by adding the OptionalNames string value. If three or more NetBIOS names are required, use the multi-string value with the same name. Figure A shows the name VSERVER1 added to an existing server. Figure A

Click the image to enlarge.
This NetBIOS name is not treated the same as the server's "primary" name. To aid in name resolution, I recommend that you add a DNS CNAME record that points to the server's primary name. Note: Editing the registry is risky, so be sure you have a verified backup before making any changes.

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About

Rick Vanover is a software strategy specialist for Veeam Software, based in Columbus, Ohio. Rick has years of IT experience and focuses on virtualization, Windows-based server administration, and system hardware.

3 comments
seanferd
seanferd

NETBIOS names is to review the proper setup, so that queries don't depend on being forwarded to an internet DNS server to get an NXDOMAIN response so they can be resolved locally. (Ugh.) Same applies to DNS configuration in a domain. Upwards of 90% of all internet DNS queries are junk. Sorry, just a pet peeve. But an interesting article, indeed.

pjboyles
pjboyles

In addition to the WINs entries and CNAMEs, consider if an SPN (Service Principle Name) should be registered as well. This will depend on what your are using your server to perform. So, when adding names to your server consider: CNAME WINS optional names SPN (Service Principle Name) (As required) Things like print server, database server, web server may all need SPNs. A final consideration is if there are any certificates associated with the name. They may need to be updated as well and added to the server.

b4real
b4real

Peter: Good point on certificates. This trick, at face value, will cause an issue with any installed certificate as they will (presumably) go via the primary name.