I have two NIC's on my Server 2003 running Exchange 2003. I though it might be useful to connect the second NIC to the network to load balance mail traffic. I assigned an IP, subnet and DNS address to the second NIC. It is active and shows activity most of the time so I assume that traffic is being balanced between the two cards. I now keep getting NetBT Errors in the Sytem Event Viewer saying: 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. Am I wasting my time running two NIC's on one machine on one network or is it actually good to make use of both of them? If it is good practice to run both NIC's, how do I avoid the NetBT errors?

Yes, you are wasting your time. If you think that one NIC cannot carry the traffic (which is unlikely in my opinion), consider teaming the NICs. DO not multihome the server. The error messages are to be expected with a multihomed server. You have two IP addresses associated with the server's name. You could try disabling Netbios over TCP/IP on one NIC, but I would disable one NIC or team them.Bill