BGP sessions timeout over port channel Layer 2

[m.arancibia]

Hi,

I have one router (CISCO7609-S) and had configured one port channel with 2 Gig interfaces.when I put no shutdown the second interface the BGP sessions fall down by timeout after 3 minutes(BGP flapping).

The interfaces are in the same module.

Version 12.2(33r)SRC3

interface Port-channel256

description CONEXION con TASA IPCUY02 - Cuyo

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 458,459

switchport mode trunk

mtu 9216

logging event link-status

logging event trunk-status

logging event bundle-status

logging event spanning-tree

!

interface GigabitEthernet1/47

description CONEXION #2 A DWDM-TASA G5/4 <-> Router TASA IPCUY02

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 458,459

switchport mode trunk

mtu 9216

logging event link-status

logging event trunk-status

logging event bundle-status

logging event spanning-tree

channel-group 256 mode active

!

interface GigabitEthernet1/48

description CONEXION #1 A DWDM:VLE5200-02-slot1-port1-TASA - G3/1 <-> Router TASA IPCUY02

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 458,459

switchport mode trunk

mtu 9216

logging event link-status

logging event trunk-status

logging event bundle-status

logging event spanning-tree

shutdown

channel-group 256 mode active

!

[Amit Singh]

Please paste your L3 and BGP configs from both the sides.

[m.arancibia]

Hi Amit,

I have the information about de local router.

Thanks a lot.

Mario

[Giuseppe Larosa]

Hello Mario,

during this time when you try to add the second member link are you able to ping the BGP endpoint ?

my guess is that something happens on the bundle.

It could be a good idea to do the following:

shut both member links

use interface range to perform a no shut

Other collegues have reported in other threads that timing is a key factor on LACP negotiated bundles

Hope to help

Giuseppe

[m.arancibia]

Hi Giuseppe,

Yes, during this time our customer was able to ping.

Is dificult to shut this interfaces because the router is in production.

Thanks a lot.

[Giuseppe Larosa]

Hello Mario,

to reproduce the BGP flow also the source should be the same as in the BGP session

if it is already so I don-t understand what is the issue.

For testing what I have suggested before you need to ask for a maintanance time window

Hope to help

Giuseppe

[m.arancibia]

Hi Giuseppe,

I already suggested the same to our customer.

The info is poor to begin a good troubleshooting.

Regards

[m.arancibia]

finally de problem detected is that the BGP sessions are closing by time out. In both sides are registering the same message...

BGP: 200.63.150.229 connection timed out 180940ms (last update) 180000ms (hold time)

The port-channel not have errors.