MAC Flapping Issue

shekhardas8 · ‎11-18-2014

Dear Folks,

I am working with a IT organization as network administrator, at client site we are getting the MAC FLAPPING issue since 1 month, due to that some time it completely down my whole network. Scenario is like that, we are using Ruckus AP and Zone director as a WLAN controller which is directly conecteted with our core switch. Rest of indoor AP's are connected with Distribute and access switch. Now since 1 month we are getting in core switch below mention notification -

#sh log

Log Buffer (8192 bytes):

889842: Nov 18 13:46:37.182 IST: %SYS-5-CONFIG_I: Configured from console by iympladmin on console
889843: 001585: Nov 18 13:47:09.724 IST: %SW_MATM-4-MACFLAP_NOTIF: Host c4d9.879b.cf99 in vlan 13 is flapping between port Gi1/1/4 and port Gi1/1/3 (nhcin-sjp01-2)
889844: Nov 18 13:49:17.806 IST: %LINK-3-UPDOWN: Interface GigabitEthernet2/0/37, changed state to up
889845: Nov 18 13:49:19.818 IST: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet2/0/37, changed state to up
889846: 001586: Nov 18 14:04:57.394 IST: %SW_MATM-4-MACFLAP_NOTIF: Host c4d9.87aa.d584 in vlan 13 is flapping between port Gi2/0/41 and port Gi2/0/35 (nhcin-sjp01-2)
889847: 001587: Nov 18 14:13:39.784 IST: %SW_MATM-4-MACFLAP_NOTIF: Host 0008.2292.1440 in vlan 12 is flapping between port Gi2/1/2 and port Gi1/1/4 (nhcin-sjp01-2)
889848: 001588: Nov 18 14:15:35.735 IST: %SW_MATM-4-MACFLAP_NOTIF: Host 1c3e.843e.c441 in vlan 13 is flapping between port Gi2/0/41 and port Gi2/0/35 (nhcin-sjp01-2)
889849: Nov 18 14:23:23.346 IST: %SW_MATM-4-MACFLAP_NOTIF: Host 14f6.5afa.ecb9 in vlan 12 is flapping between port Gi2/0/37 and port Gi2/0/35
889850: 001589: Nov 18 14:23:23.415 IST: %SW_MATM-4-MACFLAP_NOTIF: Host 14f6.5afa.ecb9 in vlan 12 is flapping between port Gi2/0/37 and port Gi2/0/35 (nhcin-sjp01-2)
889851: Nov 18 14:32:33.860 IST: %SW_MATM-4-MACFLAP_NOTIF: Host c0cb.3886.30cb in vlan 13 is flapping between port Gi2/0/41 and port Gi2/0/35
889852: 001590: Nov 18 14:32:33.954 IST: %SW_MATM-4-MACFLAP_NOTIF: Host c0cb.3886.30cb in vlan 13 is flapping between port Gi2/0/41 and port Gi2/0/35 (nhcin-sjp01-2)
889853: 001591: Nov 18 14:33:05.755 IST: %SW_MATM-4-MACFLAP_NOTIF: Host 843a.4b15.187a in vlan 12 is flapping between port Gi2/0/41 and port Gi2/0/35 (nhcin-sjp01-2)
889854: 001592: Nov 18 14:33:07.017 IST: %SW_MATM-4-MACFLAP_NOTIF: Host 6c88.14a0.93d8 in vlan 12 is flapping between port Gi2/0/41 and port Gi2/0/35 (nhcin-sjp01-2)
nhcin-sjp01#

As mentioned in msg 12 & 13 VLAN is our WLAN.

After getting this msg automatically all network goes down, I need to shut down the associated port winch is directly or indirectly connected with AP, and after some time it will work properly.

Now I need some mechanism which can be block the duplicate source mac address to preventing from this kind of scenario.

Regards,

Shekhar

devils_advocate · ‎11-18-2014

I have a few questions....

1. Are those MAC addresses actual Wireless Hosts? i.e have you traced them?

2. Are the SSID's set to tunnel?

3. Do you have one ZoneDirector or two?

On the Ruckus controllers, the default is not to tunnel the SSID's which means the AP's have to be set as Trunk ports and MAC flaps can occur if clients are roaming.

shekhardas8 · ‎11-18-2014

Hi Devils,

Answer is in below -

1. Are those MAC addresses actual Wireless Hosts? i.e have you traced them?

= Yes, those are actual wireless MAC add, I have check in zone director controller.

2. Are the SSID's set to tunnel?

=No

3. Do you have one ZoneDirector or two?

=Two, both of them are connected with core switch.

I have been confirmed about that if wireless users are roaming between two AP or more it will appear the same error msg, now what would be the solution. ????

What extly the solution is?>

Where should i implement the solution on switch or zone director?

Please suggest!!!!!

devils_advocate · ‎11-18-2014

Are the ZoneDirectors part of a standby group?

Are the AP's set as Trunk ports?

If the issue is being caused by roaming, I don't think there is much you can do.
The users can roam faster than your switch can flush its CAM entry for that MAC address when the users move between AP's.

Is it causing any issues or are you just concerned about the log messages?