RHEL 4.0 intermittently drops IP address

[Tony Verberk.]

I have a Linux system that will intermittently drop its IP address and then about 15 seconds later it will come back. This happens off and on and sometimes will repeat itself for an hour before working normally again on its own. If I ping the IP address from the Linux box (locally) it still responds, but from another workstation it will stop responding. There is nothing in the error logs indicating a problem, but I may not have the right capture options turned on. Any thoughts on how to go about narrowing down this issue?

[Ivan Ferreira]

Check the status of the link when you have that problem with ethtool, ensure with ifconfig -a that you still are receiving packets. Ensure that no duplicate ip address is on your network, use tcpdump to diagnose the problem.

[Steven E. Protter]

Shalom,

Most likely cause is another system on the network is trying to grab the same IP address. Check it with ping from another workstation if permitted.

SEP

[Tony Verberk.]

I'll give those tools a try, I was unfamiliar with ethtool.

Based on both answers about another device, I'm beginning to think that might be the issue. So far this has happened 4-5 times. For the most part they start happening right around 7:00am, when some of our employees come to the office with their notebooks. I suppose it's possible that one of them have a home network and for whatever reason they set their IP address statically.

[Tony Verberk.]

Turns out it was a user that received an IP address from a home router and then shut the lid on their notebook and brought it to work. They plugged it into the network and it didn't get a new address.

Thanks for the help.