Solved: Host 02:01:00:00:00:00 is flapping

subodh121 · ‎06-10-2010

Hi All,

Following are cat4006 production switch lops:-

Jun 11 04:31:17.666 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
.Jun 11 04:31:47.664 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
.Jun 11 04:32:17.663 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
.Jun 11 04:33:17.665 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
.Jun 11 04:33:47.664 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
Cat4006#

As I checked on both Interface, server's are connected and switch end Interface is already configured with full duplex and speed 100.

Kindly suggest, whether it is duplex mismatch issue or any other issue from server load balacer.

Ganesh Hariharan · ‎06-14-2010

Hi All,

Following are cat4006 production switch lops:-

Jun 11 04:31:17.666 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
.Jun 11 04:31:47.664 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
.Jun 11 04:32:17.663 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
.Jun 11 04:33:17.665 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
.Jun 11 04:33:47.664 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
Cat4006#

As I checked on both Interface, server's are connected and switch end Interface is already configured with full duplex and speed 100.

Kindly suggest, whether it is duplex mismatch issue or any other issue from server load balacer.

Hi,

As Leo suggested check out the nic teaming from server side and as per the logs also it seem server nic ports both are connected with same switch and in active mode from server side,if teaming is configured in active/active mode configure in active/passive mode and see the results or configure a etherchannel from switch end for both the ports.

Hope to Help !!

Ganesh.H

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View solution in original post

Leo Laohoo · ‎06-10-2010

This means that the MAC address is showing up in two different interfaces. Either the host's NIC ports are configured for teaming or the switch isn't configured for etherchannel.

Chetan Kumar Ress · ‎06-11-2010

Hi

This is ever green issue with Cisco 4500 Series Switches.

Its an IOS Bug & Currently there is no workaround for same . (CSCdy21031)

For More Detail please refer the below link.

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/release/note/OL_3739.html

Regards

Chetan Kumar

Ganesh Hariharan · ‎06-14-2010

Hi All,

Following are cat4006 production switch lops:-

Jun 11 04:31:17.666 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
.Jun 11 04:31:47.664 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
.Jun 11 04:32:17.663 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
.Jun 11 04:33:17.665 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
.Jun 11 04:33:47.664 IST: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 2 is flapping between port Fa2/42 and port Fa2/44
Cat4006#

As I checked on both Interface, server's are connected and switch end Interface is already configured with full duplex and speed 100.

Kindly suggest, whether it is duplex mismatch issue or any other issue from server load balacer.

Hi,

As Leo suggested check out the nic teaming from server side and as per the logs also it seem server nic ports both are connected with same switch and in active mode from server side,if teaming is configured in active/active mode configure in active/passive mode and see the results or configure a etherchannel from switch end for both the ports.

Hope to Help !!

Ganesh.H

Remember to rate the helpful post