11-20-2008 12:32 AM - edited 03-04-2019 12:25 AM
Hi All,
I have spent quite long to fix the flapping port, How to fix this problem?
---------from the log------------
Nov 15 11:47:52 CCT: %C4K_EBM-4-HOSTFLAPPING: Host 00:13:E8:73:5A:47 in vlan 66 is flapping between port Gi1/13 and port Fa3/12
Nov 17 12:11:12 CCT: %PORT_SECURITY-2-PSECURE_VIOLATION: Security violation occurred, caused by MAC address 000e.5308.f3bd on port FastEthernet3/4.
Nov 17 12:31:48 CCT: %C4K_EBM-4-HOSTFLAPPING: Host 00:1D:E0:8B:8E:99 in vlan 62 is flapping between port Fa3/10 and port Gi1/17
Nov 17 15:05:17 CCT: %C4K_EBM-4-HOSTFLAPPING: Host 00:16:6F:60:DE:AB in vlan 62 is flapping between port Gi1/15 and port Fa3/10
Nov 17 18:40:16 CCT: %C4K_EBM-4-HOSTFLAPPING: Host 00:1B:9E:AB:C3:F7 in vlan 62 is flapping between port Gi1/17 and port Fa3/10
Nov 17 20:35:19 CCT: %C4K_EBM-4-HOSTFLAPPING: Host 00:16:6F:60:D5:8E in vlan 66 is flapping between port Gi1/13 and port Fa3/12
-- cut --
Thanks
11-20-2008 07:17 AM
you should have a good idea of your network topology in order to do this. issue a showmac-address-table address
11-20-2008 07:25 AM
This can also happen when you have wireless access points and the client is roaming between them. Make sure that you're not overly redundant on your switches because I just went through this. After cleaning up, I don't see flapping at all.
--John
11-20-2008 07:51 AM
Thanks John,yes at the access switches we put many APs.What do you meant by "after cleaning up"?
~sam~
11-20-2008 08:02 AM
We had multiple redundant links between switches, and then the servers were connected to each switch. It was a mess. I removed many of the links and left only two.
Do you have all of your SSIDs in the same VLANs across the ports? In other words, do you have it like:
guest - vlan 100
secured - vlan 105
If that's the case, and the access points are all configured this way, you shouldn't see a flapping I wouldn't think. I would verify that it's an access point in these ports that are flapping, and then work backwards from there.
--John
09-09-2014 02:32 AM
Hi John,
We are also having simmiler issue. WiFi users MAC moving between different Wireless controllers (as different APs registered on different controller) causing High CPU on 4506 switch (where WiFi VLANs created & Controllers are connected) nearly 98% .
What can be done to avoid this ?
09-09-2014 03:14 AM
I don't know if this information can help you, but if you set the mac address table aging time to 1 second ? (mac address-table aging-time 1)
11-20-2008 07:53 AM
hey sam
If you have your wireless access points in VLAN 62, then u dont need to worry abt this flapping. This is due to the roaming of users between the accespoints.
HTH
Ullas
10-03-2012 12:14 PM
it can also happen, if there is a hub, and a user connect both end of hub with cisco switch. thats what happened to us few times, and currently , i am looking for a solution, any thoughts to avoid my partocular case?
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