Problem: I was called out yesterday to fix a network problem regarding connectivity to the server. Certain users were able to access the internet but couldn’t connect to the server, exchange/file server (same server). If you would try to acces server shares or Outlook, you would get an error saying that the server is unavailable. I would ping the server IP adress and all was fine with no dropped packets. This was only with certain computers not everyone on the network, which made me think it might be a workstation issue.
Solution: Turns out it was a server issue. The problem in my troubleshooting was that I was pinging the IP address of the server instead of the NetBIOS name. When I pinged the NetBIOS name, it returned an IP address that I didn’t know was active. Of course, the ping returned no response to host. Turns out the server had two NICs with IP’s assigned to both but only one patch cable plugged in.
I could have done one of three things:
- Plug in the 2nd NIC to the switch
- Remove the IP from the NIC and remove that IP entry from DNS so it wouldn’t resolve the NetBIOS name to that IP anymore
- Remove the IP fro the 2nd NIC and add it to the NIC plugged into the network.
I chose the 1st option because that is what they wanted. After we plugged it in, all was well with the world. Once again, a simple solution to a problem that wreaked havoc on it’s use.