[c-nsp] problem with VPC port-channel between Cisco 3550 and pair of Nexus 5020

[Andrew Jones]

Hey,

This is expected behaviour with nexus 5k running spanning tree bridge assurance connecting to a switch not running bridge assurance (ie catalyst switches) 

You need to either disable bridge assurance on the 5k, or change the port channel on the 5k to "spanning-tree port type normal" to disable bridge assurance on that port channel only.

Cheers,

Andrew Jones
Alphawest

-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Starbug
Sent: Thursday, 24 May 2012 12:15 PM
To: Tom Mikelson
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] problem with VPC port-channel between Cisco 3550 and pair of Nexus 5020

Hi Tom,

you should take a look at the spanning tree port type on the nexus:

switch# configure terminal
switch(config)# interface ethernet 1/8
switch(config-if)# spanning-tree port type network
On nexus switches, this sets spanning tree to expect a switch on the other end of the link.


regards,

AK

On May 23, 2012, at 10:54 AM, Tom Mikelson <tmikelson at gmail.com> wrote:

> Physical links are up, cdp neighbor shows all devices
> Nexus 5020 pair configured with working VPC link on VLAN 11.
> Port-channel 64 on both Nexus 5020s show blocked for spanning-tree VLAN 11.
> 
> ***** Nexus 5020s *****
> 
> interface port-channel64
>  description TEST
>  switchport mode trunk
>  switchport trunk allowed vlan 11
>  speed 1000
>  vpc 64
> 
> interface Ethernet1/8
>  description TEST
>  switchport mode trunk
>  switchport trunk allowed vlan 11
>  speed 1000
>  channel-group 64 mode active
> 
> ***** Cisco 3550 *****
> 
> interface Port-channel64
> description TEST
> switchport trunk encapsulation dot1q
> switchport trunk allowed vlan 11
> switchport mode trunk
> !
> interface GigabitEthernet0/1
> description TEST_to_5020_A
> switchport trunk encapsulation dot1q
> switchport trunk allowed vlan 11
> switchport mode trunk
> channel-group 64 mode active
> !
> interface GigabitEthernet0/2
> description TEST_to_5020_B
> switchport trunk encapsulation dot1q
> switchport trunk allowed vlan 11
> switchport mode trunk
> channel-group 64 mode active
> !
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/