I do not have a spanning tree loop. I work in a manufacturing environment and roaming is prevalent. I don't want to see mac flaps or host flap messages on the wireless ports, I only want them for STP. How do I turn off one and not the other. Cisco, 4506 Thanks


One thing to consider is the rate of flapping. Having worked with a wireless environment with no channel plan or power adjustments and automatic adjustments and channel selection disabled, constantly seeing MAC flap notifications is indicative of a problem on the wireless side of your network.

Working with WAPs that allow you to adjust, either manually or automatically, the Tx power settings on your WAPs, you'll want to overlap your wireless coverage areas per WAP, called a cell, by about 40-60% to start out with and then dial that back until you've got effective coverage while minimizing WAP hopping from stationary clients. What you want to avoid is the overhead of having stationary clients flapping between WAPs, especially WAPs running in "bridge mode" ( Aruba terminology and the default behavior for Aerohive ), and the overhead of switches relearning port associations.

I'm not entirely certain, so take this with a grain of salt, but I think that learning MAC addresses is not an ASIC/forwarding plane operation, so you're using CPU cycles when this takes place.

Cell tuning can reduce hopping/flapping, but the roaming clients will remain. Another way to reduce the impact for network monitoring is to send all of your logging back to a syslog server which will allow you greater control over what you're viewing and how and possibly even discard notifications that you don't want to retain. Having greater flexibility here will make it easier to differentiate between normal roaming and spanning-tree issues.

I found this earlier discussion which might be informative: Mac-flap due to roaming clients on wireless.


(I'm not sure what you mean w.r.t. STP vs. any of the other reasons for macflaps.)

There doesn't appear to be any way, at all, to disable this. Roaming wireless clients are simply going to be an unavoidable reality.

I'm assuming you don't have wireless lan controller(s) tunneling traffic back from each AP to the controller. That would, in theory, isolate clients from the switch(es).

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