MAC flapping on WLC ports

Hi all,
I've been getting
.Feb 23 10:59:50: %C4K_EBM-4-HOSTFLAPPING: Host 7C:E9:D3:9A:DC:99 in vlan 1 is flapping between port Gi3/2 and port Fa4/14
.Feb 23 11:00:01: %C4K_EBM-4-HOSTFLAPPING: Host B8:EE:65:71:55:12 in vlan 1 is flapping between port Fa4/14 and port Gi3/2
.Feb 23 11:01:14: %C4K_EBM-4-HOSTFLAPPING: Host 18:CF:5E:FD:41:B8 in vlan 1 is flapping between port Gi3/2 and port Fa4/14
entries on my core switch.
I get the same error for different MACs but always the same 2 ports - Gi3/2 and Fa4/14
The topology looks like this:
both WLC are connected to the same core switch:
Core 2 has WLC-2 connected to Gi 3/2 and Core 2 has C2960S connected to Fa4/14, C2960S has WLC-1 connected to Gig 0/24
Any idea on why the WLC links are showing MAC Flaps?
thanks for the support,

Hi mgonzalez15,
MAC flapping logs within a wireless environment is an expected behavior. The reason of these messages is that wireless hosts (as opposed to wired hosts) are able to roam and can be connecting to other APs/WLCs across your campus in matter of seconds.
HTH,
Julio

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Large amount of traffic with 152x mesh and mac-flap

We have just had a Mesh designed by an external company, and when we plugged it in we began have large numbers of mac-flap notification and more than 700mb of traffic sent across our data network.
Our setup includes 2 5508 controllers and 9 152x APs
3 APs (RAP) with their 5.8 antennas are within close proximity on a vertical pole pointing to the other 6 about 1000mtrs away in an arc. With their ethernet ports plugged into the same switch (native vlan 111) as WLC1 (which is LAG'd to two ports)
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Andrew,
the proximity of the antennas shouldn't cause the mac-flap notification, nor should the LAG connection cause this. That's more and indication that the client is flopping between ports on the switch, which generally happens when you are not configured for LAG on the WLC, nor a port-channel on the switch.
the mac address that is being reported in the mac-flap. Is it a client or is it the MAPs?
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HTH,
Steve
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MAC Flapping Issue

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

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!!!!!

Mac flap

Hello,
I came across an issue with and cisco 1841 fa0/1 plug into a 8 port cisco switch (G0/1)
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20
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Hi,
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encapsulation dot1Q 30
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switchport mode trunk
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Hi,
I have 16 switches and 3 servers in my network.In server room,i have one cisco WS-C2960S-48TS-L and one WS-C2960S-24TS-L connected to each other.Two eth ports of each server are being timmed and connected to the 2 switches.Every thing is fine but i am getting mac-flap log in both switches.can anyone tell me how can i stop this?
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*Feb 1 08:24:28.382: %SW_MATM-4-MACFLAP_NOTIF: Host 0015.5d07.1903 in vlan 101 is flapping between port Gi1/0/48 and port Gi1/0/3
*Feb 1 08:26:34.992: %SW_MATM-4-MACFLAP_NOTIF: Host 0015.5d07.1e01 in vlan 101 is flapping between port Gi1/0/48 and port Gi1/0/6
*Feb 1 08:25:40.351: %SW_MATM-4-MACFLAP_NOTIF: Host 0015.5d07.1e05 in vlan 101 is flapping between port Gi1/0/24 and port Gi1/0/15
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Hello
It occurs when you have a loop between the switches relating to ports bypassing the stp process and enter forwarding state either due stp being turned off or having portfast enabled.
when you have a server connectiing itself to two switches on portfast enabled ports, this can cause this type of issue you are seeing- Check if this is the case and disable the portfast feature on those ports
For trunk ports or if port aggregation check the link negotiation type (usually LACP for servers) is applied the same on both sides of the etherchannel and teamed server nics
res
Paul
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jonesl1 wrote:I am having an issue at one of our remote agencies whereas we are getting numerous mac-flap notifications on our switches.   This has become kind of a hinderance as we are getting tired of seeing these messages.   The end users havent been complaining, but the log messages are annoying. It's usually occurring with the same mac-addresses over and over.   Upon further investigation, we found the mac-addresses are all on laptops which have both wireless and wired nic's.    There are wireless AP's (cisco 1242's) in use which they can connect. We also found where the error is popping up as they move from wireless into docking into their docking station which has a lan cable attached.    I was under the assumption that the wireless mac and wired mac were different numbers and therefore if the wired was up simultaneously with the wired, as it switched over, they shouldn't get a flap.    How can I correct this....or is it correctable?I have attached a diagram to show my scenario, keep in mind those are just a few of the MANY msg's we have been receiving.   If anyonecan explain this to me, I'd appreciate it.
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