I have a strange problem with my Windows 2003 Server. Since last week the server has intermittently become inaccessible. It will be working away fine and all of a sudden nobody can access it. You can't ping the server nor can you ping any hosts from the server itself. Usually if you wait a while it comes back of it's own accord but this can sometimes take hours. Rebooting the server once or twice usually fixed it for a while but today I rebooted about 6 or 7 times with no luck and then I just left it logged in and after about 20 minutes it came back "online" and has been fine for the past 2 hours or so.
It doesn't seem to be software related as I disabled all firewalls and anti-virus software. I also restarted in safe mode with networking and it was still down under this setup. I am thinking there is a hardware issue with the NIC but unfofrtunately it's an old single NIC server so I need to purchase a second card to prove this theory.
When it goes down, the odd thing is that the ethernet lights always stay on and it always says connected. It seems to be sending packets ok but receiving none or very few. There is nothing showing up in the event logs and I have also tried replacing the CAT5 cable which made no difference.
Is there anything else I can do, any suggestions for narrowing the problem down further???