kernel: eth2: duplicate address detected
 

one of our server showing "kernel: eth2: duplicate address detected!", even though there is no duplicate IP address, I am using Scientific Linux CERN SLC release 4.8 kernel version : 2.6.9-89.0.20.EL.cernsmp (x86_64).

Please help, thanks in advance.

It might not be the "IP" address but rather the "MAC" address (a/k/a Hardware or HW address).

Not familiar with your distro but you should try checking underlying network config files to see if there is than one with the same MAC address. I've seen this when someone copies say the eth0 file to the eth1 file and neglects to preserve the address.

You might try running dmidecode and lspci to see if you can get information on the hardware. Running ifconfig -a should show you everthing that is there (though possibly not the duplicate if the kernel excluded it).

ifconfig ?

http://linux.die.net/man/8/ifconfig

I suppose its possible SL doesn't have it. However on checking around it appears that SL is built from RedHat Enterprise Linux (RHEL) source so it seems likely it would have it.

Whichever distro you're on you should be able to tell if you have it by typing "which ifconfig" as root (or sudo which ifconfig on those distros that don't give you a root login). Also for most Linux distros and UNIX variants there are man(ual) pages on the system itself so when you're curious typing "man <whatever>" may give you information in this case "man ifconfig". You'd always want to check your local man page instead of a generic one like the above link because there are differences in distros and in versions of the commands.

By the way if SL is RHEL based then the files the OP needs to examine would be in /etc/sysconfig/network-scripts and have names like ifcfg-eth0, ifcfg-eth1 etc.....

p.s. If you questioned "ifconfig" because you're a Windows admin I know it is "ipconfig" on Windows but that's because MS likes to pretend they didn't ...um... "borrow" things from Open Systems.