Mac address flapping on Catalyst 3560

ANDREA GELATI · ‎11-06-2008

Hi all, I have a problem with mac-address flapping, when this problem occur, lan go down for few minutes.

Catalyst 3560 is "Core" of this Lan,it is connected to 2 access switch and Stp in active on this switches

In the same segment of Lan I have 5 WLC 2106 and 21 Ap Lwapp configured in mesh mode.

Catalyst nofifications tell me that I have mac-address flapping from Access Point Port (Fa0/6), Wlc Port (Fa0/17) and Uplink port (Gi0/1).

Could do you help me?

Marco

Nov 6 14:32:03: %SW_MATM-4-MACFLAP_NOTIF: Host 001e.be27.4a46 in vlan 1 is flapping between port Fa0/6 and port Fa0/17

Nov 6 14:32:06: %SW_MATM-4-MACFLAP_NOTIF: Host 0030.05b1.c889 in vlan 1 is flapping between port Gi0/1 and port Gi0/2

Nov 6 14:32:09: %SW_MATM-4-MACFLAP_NOTIF: Host 001d.45ed.ea60 in vlan 1 is flapping between port Gi0/1 and port Fa0/20

Nov 6 14:32:09: %SW_MATM-4-MACFLAP_NOTIF: Host 001e.be27.6c8e in vlan 1 is flapping between port Fa0/6 and port Gi0/1

Nov 6 14:32:13: %SW_MATM-4-MACFLAP_NOTIF: Host 001e.be27.43f2 in vlan 1 is flapping between port Fa0/7 and port Gi0/1

francisco_1 · ‎11-06-2008

Andrew,

I am trying to guess what the problem might be because you have access points on your network but it looks like you have two users roaming from one AP to another connected on another switch. Unless the frequency of the flap is very high it should not affect in any way network performance. If you really want to nullify the roaming flapping your only solution is to disallow the mac address on the less used AP (Services/Filters).