When NetBIOS over TCP/IP Name Resolution Stops Working

NetBIOS over TCP/IP, also known as NBT, is a bad idea whose time never should have come. We all know we shouldn’t use it, or WINS for that matter; we should just use DNS everywhere. And we also know that we shouldn’t eat a lot of bacon. But if someone has a plate of bacon ready for me at the bottom of the stairs every morning, I will eat some of that bacon, every morning. And so it is for NetBIOS: in a few cases, such as when connecting to a particular VPN, I will eat the bacon of technology and just let NetBIOS resolve the host names on the remote network.

For the last 15 years, this has generally worked well. And why not? NetBIOS is grossly inefficient–firing broadcasts of all kinds around the entire LAN (and if on a VPN, the remote network) to find out who is who and what is what–but that’s like using a tennis racket to hit a ping pong ball: you’ll hit the ball, every time.

Yesterday, NetBIOS name resolution just stopped working for me. I had put my Windows 7 workstation onto the network of a large corporate customer, and noticed I could no longer reach remote VPN machines using their NetBIOS names. That’s OK, I thought, when I get back onto my home network, all will be well. But all wasn’t well, even on my home network.

After quite a bit of googling, trial, and failure, most of it involving running various nbtstat commands on my adapters or net view commands, I found that ipconfig /all showed a working computer to have a Node Type of “Hybrid“, and my failing workstation to have a Node Type of “Peer-Peer“.

To set the Node Type to “Hybrid”, I had to edit the registry as described here, using these steps:

1) Run the registry editor and open this key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Netbt\Parameters
2) Delete the DhcpNodeType value if it’s present.
3) If the NodeType value isn’t present, create it using type: DWORD.
4) Set NodeType to 8 (Hybrid).

Then I disabled and re-enabled my network adapter, and voila! I could once again use NetBIOS, both on my LAN and to reach remote hosts over VPN. Now that’s some good bacon!

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