Link agregation / etherchannel between Nortel switch and Cisco 4507

Hello everyone,

I am trying to configure our nortel switch module in an IBM blade to bond two 1 GB uplinks into a single trunk line using port aggregation to a cisco 4507. The configuration works fine with one link connected once I connect the second link after about 5 minutes i start to see packet loss and then eventually total loss of connectivity. It seems it is causing a loop in switch that spanning tree is not catching.

Our network is pretty flat with only one data vlan using vlan 1

Config on nortel
On the nortel side through the GUI i have created a trunk group and added ports EXT 1 and EXT2.

Cisco config
On the cisco side here is the configuration
interface Port-channel2
description uplink SFBNORTELSW02
switchport
switchport trunk encapsulation dot1q
switchport mode trunk

interface GigabitEthernet3/7
description Uplink to SFBNORTELSW02
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 2 mode on
!
interface GigabitEthernet3/8
description Uplink to SFBNORTELSW02
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 2 mode on

Any help would be greatly appreciated.

jdfloryAsked:
Who is Participating?
 
jdfloryAuthor Commented:
Thanks for the response.  I just figured it out.

The GUI on the nortel switch said that the trunk group was enabled but after logging into the cli i ran

/info/l2/trunk 1 and it said disabled.  Once i enabled it worked as it was supposed to.

My only guess is was not using the trunk group at all but was using DTP to trunk to the cisco and when connected the second link it created a loop.  I still not sure why spanning tree did not catch the loop.

Spanning-tree is configured and the switch that i was uplinking to was configured as the root bridge.

Kind of weird....but it is working now.

Thanks for responding
0
 
QuoriCommented:
Have you configured STP PVST on the Cisco side? Not using any link aggregation protocols on the server side of things?
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.