Switch connected to WAP321 stops responding

[Andrew Griggs]

On two separate sites we have installed WAP321s and on both sites we are seeing an unusual problem.  After several hours, the switches the WAP321s are connected to stop responding, forcing a power-cycle of the switch.  They then work perfectly then for several more hours.  We have confirmed that both the switches (Netgear) and the WAP321s have the latest firmware.  On the first site we suspected a dodgy switch, as swapping the Netgear managed unit out for an old 3COM unmanaged switch resolved the problem, but now we have experience the same issue on a separate site with an unmanaged Netgear switch.  Both sites have only manifested the problem since the Cisco's were installed, and disconnecting them from the switch cures the problem.

Any suggestions?

EDIT, I'm starting to see this happen more with Apple devices connecting to the AP, I'm trying to narrow this down further.

[chrebert]

Hello Andrew,

I know your post was from quite a while back, but I was wondering if you ever got this resolved.

Often time Apple devices send out a lot of Bonjour and other multicast traffic, which can overload switches that don't know how to handle it properly.  

I would suggest getting a packet capture off the the network and taking a look for an unusual amount of multicast or broadcast traffic.

Hope that helps a bit,

Christopher Ebert - Advanced Network Support Engineer

Cisco Small Business Support Center

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[Andrew Griggs]

Hi Christopher,

This is exactly what I've narrowed the problem down to.  It looks like excessive multi-casting has been locking the switches - we put in a switch with storm control to test, and the problem disappears.  I've resolved the issue by rate-limiting the multi-casting traffic to one-fifth of the default values.

Kind regards,

Andy