A problem has appeared on one of my LANs which presents itself as a duplicate IP address. However there definitely isn't a real duplicate IP out there. What happens is on a Windows PC I get the 'duplicate IP address detected' message and on a Solaris box the more helpful kernel warning 'Hardware address xx:xx:xx:xx:xx:xx trying to be our address yy:yy:yy:yy:yy:yy'. The network runs fine for ages, then suddenly the problem hits and everything goes nuts for either seconds or a few minutes. Then it clears on its own and all is fine again. There are several devices on the LAN that do proxy ARP, and I have a feeling something is messing up ARP and responding with incorrect MAC addresses to ARP requests. So...
1) Can anyone give me a potted explanation of proxy ARP and how it might relate to my problem (I understand the ARP mechanism well)
Thanks for the deluge of replies on this one
On further investigation I interpreted the error message (see previous post) from the Solaris box wrongly. It actually reads 'Hardware address <correct MAC address of this server> trying to be our address <corect IP address of this server>'. So this machine is complaining that it is having an IP address conflict with itself! How can a Solaris box be getting confused about its own MAC address???
No, it wasn't that. And I didn't really solve it either. It happened on and off for a couple of weeks then just disappeared on its own. And there was no device replacement or change etc that might have been responsible. I remain mystified
Don't you just hate these problems that come and go without reason?
I'm currently trying to figure out why we are experiencing jittering problems with our IP Phone network and while researching, I've found that some switches are showing unicast traffic across their ports which shouldn't be seen!