A duplicate name has been detected on the TCP network 1

[trveer]

Hi all,

I have mixed mode setup with windows 2000, NT PDC / BDC.

Since yesterday one of my Win2000 Server event viewer is showing the following error :

" A duplicate name has been detected on the TCP network. The IP address of the machine that sent the message is in the data. Use nbtstat -n in a command window to see which name is in the Conflict state. "

From this system i can view my LAN, ping any system in the LAN. At the same time, none of my LAN systems are able to ping this win2k server or browse the system from Network Neighbourhood.

I gone through the steps given for this problem in several forums, but unable to fix it sofar. The hex numbers given in the error 4319 are pointing to my PDC / BDC systems only. None of the LAN Systems have the same name like this win2k server.

I installed service pack 4 too. But still the problem exists.

Urgent help needed.

 

[pgearle]

I'm seeing the same message in my BackupExec logs on a Win 2000 server as well. What do I need to do to run NBSTAT? Just typing in NBSTAT -N from the command prompt gives me the message 'the name specified is not recognized as an internal or external command, operable program or batch file'.

 

[trveer]

Hi,

The command is NBTSTAT -N, you are missing t.

 

[RockChalk]

I'm having the same problem with a server with dual nics. Can they be conflicking each other?
trveer does your server have dual nics?

RC

 

[Tekmazter]

Man in the middle attacks will do this. Otherwise, check your dhcp leases and find the one it's referring to, dump it, and reboot the box.

 

[BarryMVS]

To all,

Do any of your servers have two or more network cards attached to the same IP class ntwork?

If so, then this is where you are getting the duplicate name from. The server is seeing itself via the other card!

With stand-alone, non-domain controllers, this isn't an issue, but for domain controllers, it is a big problem and often drops the server from the network.

To test this, disable one of the NICs on your server and restart the server. If this resolves the problem then that is the cause.

Hope this helps,


Barry

ICT Network Administrator
IT Services Manager

 

[RockChalk]

Barry,
I disabled one of my nics and the error has stopped. What is the best partices for dual nics.
This is the first server that I have purchased with dual nics installed.

RC

 

[BarryMVS]

RockChalk,

Is your server a domain server or a stand-alone?

If it is a domain, then you can only run the one NIC as far as I am aware. (I have the same problem at work!)

If it is a stand-alone basic file server, (not a PDC), then you can run both NIC's.

The server will see itself, but should still operate.
It only goes off-line if it's a PDC. (I don't think Active Directory can handle two machines by the same name, thus sees a security threat and disconnects from the network.)

I am still trying to resolve this and if I find a solution, I'll let you know.

Barry

ICT Network Administrator
IT Services Manager