As far as the duplicate MACs go, it sounds like you have a layer-2 loop. Especially considering that all of your servers are experiencing the problem. When they ARP to verify that no other station has their IP, they see their own ARP and assume that another station is doing the same thing.
Layer-2 Loops will also cause MACs to appear to be sourced from different switches in the network. Is STP enabled everywhere? Mismatched channelling will also cause the same behavior. Firesox wrote: > I have a bunch of 3500XL switches thruout my customer's lan. > They are having a problem with unknown mac keep appearing and disappearing > from the network. > > I can trace the mac-address of the unknown station by "show mac" from the > swtich CLI. > What's strange is that it appears at one switch, but a minute later it > appears in the different switch. > > what's even more strange is that all NT/2000 servers log shows there is an > IP conflict with this mac address. > Of course, the servers IP function stops due to this duplicate IP, but comes > back in a few minutes. > All the servers report the duplicate IP comes from the same mac address. > > Has anyone seen this problem? > > Thanks > **Please support GroupStudy by purchasing from the GroupStudy Store: > http://shop.groupstudy.com > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=73892&t=73868 -------------------------------------------------- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
