Do I need WINS?

WINS is a feature that I’ve debated a little recently. It is a lot of uncertainty connected to the role WINS has (or would have) in a modern Windows infrastructure. Let’s start with the beginning

NETBIOS

NETBIOS is strictly speaking an API (and not a network protocol) which allows you to assign a name to a computer which has an IP address. The NETBIOS name has no relation to the hostname (DNS) and nothing prevents a host from having a completely different NETBIOS name and hostname. The NETBIOS name is limited to 15 characters and provides no hiearchy. There are four types of nodes, which tells you how NETBIOS names are resolved to IP.

  • B-node: 0x01 Broadcast
  • P-node: 0x02 Peer (WINS only)
  • M-node: 0x04 Mixed (first broadcast, then WINS)
  • H-node: 0x08 Hybrid (first WINS, then broadcast)

If you run “ipconfig /all” on your computer then “Node type” in the top will tell you which node type your computer has, and as you can see it either looks up in a WINS database or it does a broadcast, or both depending of the node type.

WINS

WINS can in many ways be compared to a DNS server as WINS contain a list of all NETBIOS clients and their IP address, he list can be dynamically updated and its content can be replicated to several servers by setting up push and/or pull replication. But unlike DNS, NETBIOS and WINS are not required for internet access.

So do I need WINS?

Short answer: No you don’t need WINS (nothing will break if you don’t implement it), but you may want to consider it.

Longer answer: The importance of WINS has been greatly reduced over the last decade. In the old NT4 days it was absolutely crucial and today it can be implemented to reduce broadcast traffic. Your benefit of WINS depends very heavily on your environment (OS version on your clients, network segmenting, bandwidth etc). A VDI environment with Windows XP (yes, they exist) is a good candidate for where WINS can help. I see however few reasons not to implement WINS as it requires hardly any resources and can reduce your broadcast traffic. The other option is to disable NETBIOS over TCP/IP but you run a risk of breaking quite a few services. File and printer shares needs NETBIOS and a large number of 3rd party application will also stop working. If you want to disable NETBIOS then make sure you do a lot of research first.

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