Switchport Flapping

[ETHELBERT EZEAPUTA]

Hello All

I recently deployed WLAN and during integration of the lastmile devices, I noticed that the Catalyst 2960-C series PD switchport flaps when i connect more than three host (radios) to the switch.

With just two radios connected to the switch, everything is fine, but with additional host connected to the catalyst switch, the switchport flaps. Please, find below the error message.

*Mar 14 00:09:08.004: %SW_MATM-4-MACFLAP_NOTIF: Host 0027.22cc.8afe in vlan 1 is flapping between port Fa0/1 and port Fa0/4

Please, how can i resolve this issue.

Regards,

Ethelbert

[Peter Paluch]

Hello Ethelbert,

The message is basically telling you that frames from the sender 0027.22cc.8afe are arriving both through ports Fa0/1 and Fa0/4 which should not happen. This may either be caused by a switching loop or by an improperly used shared medium (such as a station sending its frames alternately through different access points).

A couple of questions:

• What is connected to the Fa0/1 and Fa0/4 - are these the access points?
• What kind of access points are you using? Are these Ubiquity APs?
• Are your APs perhaps configured in bridge mode, or is it by any means possible that one of the APs actually associates as a client to another AP?
• Are you able to find out to whom does the MAC address 0027.22cc.8afe belong?
• Do the APs form some kind of cluster that would externally behave like a single device with a single identity, perhaps even a single MAC address?

Best regards,

Peter

[get_rthym]

I'm not expert but can u do "clear arp" n see it resolves issue, just a opinion.

Thank you

Sent from Cisco Technical Support iPhone App