Question : Having connection problems between two Windows servers.

Products used:

Windows 2003 Servers
Symantec Backup-Exec
Cisco 3750 Switch

The run down:

I have a backup server (192.168.18.101) who backs up 3 other servers (192.168.18.107-109). The server was backing up fine all servers, but now fails to backup server 192.168.18.109.

Server 192.168.18.109 had a second NIC enabled at some point with an IP of 10.1.1.x, this last NIC was disabled about 15 days ago, and ever since, the backups started failing.

I have no reason to believe that disabling the NIC could be the problem, since the backup server cannot even talk to the 10.1.1.x network, so it must talk to the servers on the 192.168.18.x network.

I have been on the phone with Symantec support (up to level 3 supervisor) and we did some major troubleshooting, but in the end they were able to demonstrate that there is a network problem, which I couldn't believe since the backup was working fine before.

I re-enabled the NIC that was on the 10.1.1.x network to make sure that wasn't the problem, and it isn't, the backup still fails.

The issue:

Now, when I do a ping -t from 192.168.18.101 to 192.168.18.109, sometimes it times out, others it works fine, and I will let it sit there for about 8hrs, and I get intermittent drops on the connection, some lasting as long as 10 minutes.

Both servers plug into the same switch, the switchports are configured for the same VLAN (192), and are configured for 100MB full duplex, the NICs on the servers are also configured for 100MB full duplex.

The backup server can ping the other two servers without ever dropping a single packet.

When connection is working fine, I can do ping -a and it will resolve the name of the servers just fine, including the one with connection problems.

What I've done:

- Replaced the ethernet cables to both these servers.
- Changed the switchports for both servers, and configured properly.
- Windows firewall is completely turned off and disabled.
- Antivirus is completely disabled.
- Used different NICs on the servers
- Cleared DNS cache
And of course restarted about 50 times already.


Still intermittent connection problems!!!

Is there something in Windows that I'm missing?

Answer : Having connection problems between two Windows servers.

you can test your ram with memtest86+ from the ubcd :  http://www.ultimatebootcd.com/      
test them in pairs, or groups.
it looks like your power supply took a hit, and may have damaged the board, or components as well.
so test all parts first - you may have more than 1 bad device...