%RTD-1-ADDR_FLAP: FastEthernet0/19 relearning 5 addrs per min

[ecafracs]

I'd been receiving this error from my switch and I can't seem to understand why this is so.
Any help will be much appreciated.

 

[eurobadger]

Hi

It looks like you have a loop in your network. Check if Spanning Tree has been disabled on the ports concerned, and turn it on if it has.

This can be seen when you are configuring etherchannel or 802.1q trunking... see

http://www.cisco.com/en/US/products...s_configuration_example09186a0080094789.shtml

EB

 

[eurobadger]

You might also want to see

http://www.cisco.com/en/US/products...figuration_guide_chapter09186a008007e927.html

EB

 

[ecafracs]

great link eurobadger. I'll try the config tomorrow. Actually, I'm really all drained up. Got a lot of troubleshooting today. You know, servers and routers and most of all ,end-users. he he. Thanks! Help very much appreciated.

 

[jerkiest]

I've been seeing these for almost 2 years. It is being caused on my network by roaming wireless symbol devices according to the debug of the ethernet controller.

The aP's apparently aren't letting the Cisco Spanning tree Switches know that a specific mac has "left the building" and when the Mac of the Mobile Unit consequently shows up on another AP and therfore Switch..,,,Spanning tree is saying there's a loop and relearns all addresses. I feel neither Symbol or Cisco has claimed responsibilty or moved to rectify this. IT people ,,,really,,,,sometimes they can be so weak.

 

[ecafracs]

I was able to resolve the problem by sniffing traffic over the network. A defective NIC,patch cable,can be fatal enough to cause the problem. There was also another incident wherein the bug in th IOS caused the issue, an update of the IOS cleared the error.