Tuesday, August 23, 2011

Trunking an Extreme 450a to a Cisco 3750 via LACP

I've seen several attempts of this elsewhere on the 'net but most had a few errors that caused issues. Here's the approach that worked for me:

Extreme side: Assuming ports being assigned are not untagged on any VLANs or in use by anything else

Assuming port 5,6,7,8:

Enable sharing 5 grouping 5,6,7,8 lacp

Add to VLANS we need to route:

configure VLANname1 add ports 5 tagged
configure VLANname2 add ports 5 tagged

Cisco commands:

Assuming 2x core switches chained, ports 37 and 38 each. 

interface range g1/0/37-38,g2/0/37-38
description temp connection to extreme core
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 48 mode active

interface port-channel48
description temp connection to extreme core
switchport trunk encapsulation dot1q
switchport mode trunk

3/22/12 update: We've finally retired the old Extreme switches. I am happy to say that this LACP trunk config performed perfectly for nearly 5 months to tie a new Cisco infrastructure to an old Extreme one.