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i have a problem for cisco catos 4232 switch.

i have entered the enable mode in cisco catos 4232 switch,but always there have been a remarks appearing all the time as follows:

2006 Feb 23 14:23:34 %SYS-4-P2_WARN: 1/Host 02:01:00:00:00:00 is flapping betwee

n port 3/34 and port 3/33

why?

thank you!

Best Respects!

guominquan

1 REPLY

Re: i have a problem for cisco catos 4232 switch.

Hi Friend,

The message indicates that your Catalyst 4500/4000 switch has learned a MAC address that already exists in the content-addressable memory (CAM) table, on a port other than the original one. This behavior repeatedly occurs over short periods of time, which means that there is address flapping between ports.

If the message appears for multiple MAC addresses, the behavior is not normal

If the error message appears for one or two MAC addresses, locate these MAC addresses in order to determine the cause. Issue the show cam mac_addr command in order to identify from where these MAC addresses have been learned. In this command, mac_addr is the MAC address that the error reports as flapping.

After you determine between which ports this MAC address is flapping, track down the MAC address. Connect to the intermediate devices between your Catalyst 4500/4000 and the device that has the problem MAC address. Do this until you are able to identify the source and how this device connects to the network.

Note: Because the MAC address is flapping between two ports, track down both of the paths.

These are other issues that can cause this message to appear

1) Server NIC redundancy problem

2) HSRP

3) EtherChannel misconfiguration

4) Host reflects packets back onto the network

Check this link for complete details of this problem and how to troubleshoot

http://www.cisco.com/warp/customer/473/176.html#subtopic1k

HTH, if yes please rate the post.

Ankur

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