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Is there a way to run NetBIOS entirely on TCP? I have an environment where UDP is not allowed. I need a way for the machines to talk to each other by name. I thought there might be a way to say that NetBIOS should run only on TCP and not on UDP. Is this possible?

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UDP is not allowed? That's... creative. – Shane Madden Oct 9 '11 at 4:48
Im having trouble thinking of any reason why – Silverfire Oct 10 '11 at 2:12
@Silverfire, indeed, I'm reminded of Catbert's favorite reason for any new policy: because I hate you. :-) – Harry Johnston Oct 10 '11 at 23:41

NetBIOS over TCP is an option on the WINS tab of the advanced TCP/IP properties of the NIC on every Windows OS since Windows 2000. The default is for NetBIOS over TCP to be enabled if the NIC is configured with a static ip address or the NIC is configured to get an ip address from DHCP and DHCP is not configuring NetBIOS.

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yeah, but I just cannot get it to work. Are you 100% sure that no UDP packets are sent when you use this option? How can I validate this? – Martin Oct 9 '11 at 8:55
from the Win2k documentation: – Martin Oct 9 '11 at 10:49
The Windows 2000 implementation of NetBIOS over TCP/IP is referred to as NetBT . NetBT uses the following TCP and UDP ports: UDP port 137 (name services) UDP port 138 (datagram services) TCP port 139 (session services) – Martin Oct 9 '11 at 10:50
This version of the NetBIOS-over-TCP protocols uses UDP for many interactions. In the future this RFC may be extended to permit such interactions to occur over TCP connections ... – Martin Oct 9 '11 at 11:07

You shouldn't need NetBIOS to allow the machines to talk to one another by name. Windows file sharing (aka CIFS or SMB) is perfectly capable of using DNS. Either refer to machines by their full DNS names, or add the appropriate suffix to the DNS search path.

The DNS name for a machine does need to correspond to the Windows computer name in order for this to work.

If you don't have a working DNS server (which I don't suppose you do if UDP is prohibited) you could instead use the hosts file to provide name to IP mappings:

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