From: Joseph Brunner (joe@affirmedsystems.com)
Date: Thu Sep 27 2007 - 03:24:28 ART
Thought I would share this with the group. Kind of freaky (this show
"CHEATERS" is on in the background, wait for the message!!!). I was
configuring my dot1q-tunnels on my rack to make two switches jump between a
middle switch.
I remember back a few weeks ago there was some discussion here that you
could do a two port dynamic channel with only one VLAN, VLAN 100!!!
Sw1 G0/13 -> F0/13 Sw2 F0/15 -> Sw3 F0/15
Sw1 G0/14 -> F0/14 Sw2 F0/16 -> Sw3 F0/16
Well, Sw1 & Sw3 go this error message
rack1sw1#sh debug
PAGP:
Port Aggregation Protocol events debugging is on
00:31:46: PAgP: Gi0/13 failed - partner saw multiple partners.
LOL, PAgP is most definitely a point-to-point protocol
This is the NON working config on SW2 doing dot1q-tunneling with all ports
in vlan 100.
rack1sw2#sh run | b 0/13
interface FastEthernet0/13
switchport access vlan 100
switchport mode dot1q-tunnel
l2protocol-tunnel cdp
l2protocol-tunnel stp
l2protocol-tunnel point-to-point pagp
no cdp enable
!
interface FastEthernet0/14
switchport access vlan 100
switchport mode dot1q-tunnel
l2protocol-tunnel cdp
l2protocol-tunnel stp
l2protocol-tunnel point-to-point pagp
no cdp enable
!
interface FastEthernet0/15
switchport access vlan 100
switchport mode dot1q-tunnel
duplex full
l2protocol-tunnel cdp
l2protocol-tunnel stp
l2protocol-tunnel point-to-point pagp
no cdp enable
!
interface FastEthernet0/16
switchport access vlan 100
switchport mode dot1q-tunnel
duplex full
l2protocol-tunnel cdp
l2protocol-tunnel stp
l2protocol-tunnel point-to-point pagp
no cdp enable
The fix is
On Sw2 put F0/14 & F0/16 into VLAN 200
So the lesson here is your dot1q-tunnel infrastructure MUST get each single
link back to exactly and ONLY one single link to form a channel. So the vlan
carrying the l2protocol-tunnel traffic must be UNIQUE in the dot1q-tunnel
infrastructure to do Pagp, lacp, etc.
-Joe
This archive was generated by hypermail 2.1.4 : Sat Oct 06 2007 - 12:01:16 ART