Etherchannel issue on cisco switch.

Unanswered Question
Mar 31st, 2009


I have configured ether-channel b/w 6500 and 3750 stack, and now the interface in ether-channel doesnt work and caused 3750 stack to go down.

I checked the interface on stack switch and found the ether-channel down, but where as the connecting port on 6500 was up.

I have already changed the fiber connections and also tried different ports at both ends but still the same issue.Hence have shut down one of the link and running without redundancy. If i enable the port then the port-channel goes down on 3750 not sure why is this happening.

Your help would be greatly appriciated.



I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
sgopikrishnan Tue, 03/31/2009 - 04:40


when a interface is in etherchannel we do not have any control protocol running between the links like LACP or Pagp.

start from basic

--first delete the interface configuration

--check for interface duplex and speed to auto and if it is fiber check for UDLD

--after deleting the configuration check for the ports are in default vlan

--check the interface is coming up without etherchannel and check for the UDLD settings

--then goto the interface mode


#sw mode access

#channel-group 1 mode on -- on both ends it should be ON mode.

then add the interface to this channel group.

--create an etherchnnel on both sides and check it out it is coming up

--any changes regarding the VLAN or IP address make changes only on the logical inteface

--still not working then enable LACP or Pagp on both end and check it out

--check for the cables also

still not working send me the configuration details and IOS information also.

Hope this helps,




This Discussion