09-20-2013 01:07 PM - edited 03-07-2019 03:35 PM
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,
01-09-2019 06:14 PM
01-10-2019 03:41 AM
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.
01-10-2019 03:59 AM
+ As workaround you have to find the port with the wrong learned mac address and shut/no shut.
04-10-2020 06:39 PM
having the same issue .did you find solution to this issue?
04-14-2020 01:23 AM
TAC asked me to implement DHCP snooping and DAI, the problem never came up again.
01-23-2019 07:59 AM
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