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New Member

Wirleless vlan MAC flapping creating packet loss on a 3560X switch?

Hello all,

In one of our offices we had an issue with mac flapping that caused extreme packet loss so that service was interrupted for the users for a few minutes.  I had a tac engineer check this out with me today and in his analysis he advised that this was happening because the switch keeps the mac address learned for five minutes by default and that when an end user is roaming the mac is being learned by more than one switch which is causing the mac flapping. 

We were further advised that if this happens again we should remove one of our AP's because this is likely a side affect of having too many AP's located in close proximity. 

Has anyone else here on the forums run into this issue?  We have plenty of offices with cisco wireless AP's and we have never had mac flapping that actually created packet loss on the switch?  The flapping was occurring between an 1140n AP and a trunk port to another switch.  When we checked the other switch we see the same output indicating mac flapping on two of the wireless vlans??

Any suggestions or feedback here on the forum would be a great help because the idea the explanation I got today seemed odd.


Thank you.





VIP Purple

Are these AP managed by a WLC

Are these AP managed by a WLC or are those Autonomous APs ?

Removing AP to fix this is not a good recommendation...


New Member

Hello Rasika, and thank you

Hello Rasika, and thank you for the reply,


We have a WLC that hosts our AP's.  I was also advised that the switch, keeps the MAC address learned for 5 minutes by default and I could try shortening that but I still think this doesn't sound right.

Do you have any ideas as to what could be causing the mac flapping?

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