MAC Flaps - Always bad or sometimes normal?

[ToryDav]

Hi,

I am investigating MAC address flapping in my event logs. I see Meraki event log reporting flaps on my switchports across a bunch of switches in this environment.

The thing is, these are either on uplink ports or access point ports. 

Am I correct to say this is normal behavior? Searching the a MAC address from one of these flaps reveals a client visible to both wired and wireless equipment. There is also non-Meraki equipment at play in the switching environment (older cisco catalyst). 

SO, to me, if the client is roaming, then the mac address could be learned on on multiple switches. Which is why I am seeing them on AP ports and uplinks. And the client tracking by MAC address could be at play here with the non-Meraki switches (which do have MR's off of some of them).

Any other thoughts that could be causing this?

[GIdenJoe · Accepted solution]

If the MAC flaps are coming from trunks leading to AP's you are only dealing with alot of wireless roaming events.  This is not harmful in any way and can safely be ignored.  Just tell the people to sit down more 😜

[ToryDav]

Thought so. Thanks !

[Marco_812]

We have noticed a lot of this on our network and have determined it is because we refurb a lot of PC laptops/tablets and Macbooks. Anymore a lot of them don't have an RJ45 port, so we use USB to RJ45 adapters, and that's what's causing our flapping because these adapters don't stay in place, they get moved from station to station during the day

[ToryDav]

Thanks for adding to this thread @Marco_812. That's an interesting point you make there.

[tlucy]

I noticed the mac address Flapping but it only start jan 1st not before?  has there been an update to the meraki switches that could cause this?