multiple mac addresses found in one interface

[wuh]

hi, there,

we have many interfaces on our access layer switches, each of them are connected with two devices, a phone and a computer, how ever, we found each of the interfaces with many mac addresses, some of them even with hundreds. The devices are not servers, only workstations.

these mac addresses are gone when we bounce the ports but eventually come back. and they dont have any entris in the ARP table.

any one expereinced this kind of issue?

Besides we have cisco NAC configured but are not forced. dont know whether this can cause the problem or not

thanks,

[ubuemebrit@gmail.com]

hello Guys...
i need your urgent responds on this issue...... can anyone help with this???

[Anouar_network]

Hello,

we have opened a TAC to cisco and below the reply:

as the MAC/ARP of the GW suddenly start to appear to be learned on a client  port, then we can apply the below as a precaution and a solution  for  such issue.                                                             
                                                                         
-          We can enable the DHCP snooping so then we can enable the    
ARP inspection feature.                                                  
                                                                         
·         These features will help to stop any spoofing for the other    
devices MACs and ARPs.  

[Anouar_network]

+ As workaround you have to find the port with the wrong learned mac address and shut/no shut.

[ade5]

having the same issue .did you find solution to this issue?

[NECsupportFCA]

TAC asked me to implement DHCP snooping and DAI, the problem never came up again.

[lopezgi]

I have the same issue with one camera producing multiple MACs. When i look up the MACs they don't exist, seem spoofed.