bgp is going down between 2 cisco ME3600 device

[Kamini_24]

from DeviceA:

114111: *Mar 28 05:23:59.400 EET: %BGP-5-ADJCHANGE: neighbor 10.30.254.1 Down BGP Notification sent

114112: *Mar 28 05:23:59.400 EET: %BGP-3-NOTIFICATION: sent to neighbor 10.30.254.1 4/0 (hold time expired) 0 bytes

114113: *Mar 28 05:23:59.400 EET: %BGP_SESSION-5-ADJCHANGE: neighbor 10.30.254.1 VPNv4 Unicast topology base removed

from session BGP Notification sent

114114: *Mar 28 05:23:59.400 EET: %BGP_SESSION-5-ADJCHANGE: neighbor 10.30.254.1 IPv4 Unicast topology base removed

from session BGP Notification sent

114115: *Mar 28 05:24:07.604 EET: %BGP-5-ADJCHANGE: neighbor 10.30.254.1 Up

114116: *Mar 28 05:25:38.068 EET: %BGP-5-ADJCHANGE: neighbor 10.30.254.1 Down BGP Notification sent

114117: *Mar 28 05:25:38.068 EET: %BGP-3-NOTIFICATION: sent to neighbor 10.30.254.1 4/0 (hold time expired) 0 bytes

114118: *Mar 28 05:25:38.068 EET: %BGP_SESSION-5-ADJCHANGE: neighbor 10.30.254.1 VPNv4 Unicast topology base removed

from session BGP Notification sent

114119: *Mar 28 05:25:38.068 EET: %BGP_SESSION-5-ADJCHANGE: neighbor 10.30.254.1 IPv4 Unicast topology base removed

from session BGP Notification sent

114120: *Mar 28 05:25:45.332 EET: %BGP-5-ADJCHANGE: neighbor 10.30.254.1 Up

from DeviceB:

:

053002: *Mar 28 05:34:15.515 EET: %BGP-3-NOTIFICATION: received from neighbor 10.30.254.14 4/0 (hold time expired) 0 bytes

053003: *Mar 28 05:34:15.515 EET: %BGP-5-ADJCHANGE: neighbor 10.30.254.14 Down BGP Notification received

053004: *Mar 28 05:34:15.523 EET: %BGP_SESSION-5-ADJCHANGE: neighbor 10.30.254.14 VPNv4 Unicast topology base removed

from session BGP Notification received

053005: *Mar 28 05:34:15.523 EET: %BGP_SESSION-5-ADJCHANGE: neighbor 10.30.254.14 IPv4 Unicast topology base removed

from session BGP Notification received

053006: *Mar 28 05:34:22.779 EET: %BGP-5-ADJCHANGE: neighbor 10.30.254.14 Up

053007: *Mar 28 05:35:53.271 EET: %BGP-3-NOTIFICATION: received from neighbor 10.30.254.14 4/0 (hold time expired) 0 bytes

053008: *Mar 28 05:35:53.271 EET: %BGP-5-ADJCHANGE: neighbor 10.30.254.14 Down BGP Notification received

053009: *Mar 28 05:35:53.279 EET: %BGP_SESSION-5-ADJCHANGE: neighbor 10.30.254.14 VPNv4 Unicast topology base removed

from session BGP Notification received

053010: *Mar 28 05:35:53.279 EET: %BGP_SESSION-5-ADJCHANGE: neighbor 10.30.254.14 IPv4 Unicast topology base removed

from session BGP Notification received

053011: *Mar 28 05:35:59.475 EET: %BGP-5-ADJCHANGE: neighbor 10.30.254.14 Up

[Olivier ARRIGHI]

Hi Kamini. This is a bit short to give any explanation. Can you please provide config for BGP, vlan interfaces, and ports involved in this config?. Also, it looks like there is a 30 second timer running the show, so check every protocol using such dead timers that could hit BGP.Tell us how are interconnected those 2 me3600.

cheers

[Kamini_24]

Device A:

interface Tunnel320

description *** A to B ***

ip unnumbered Loopback0

tunnel mode mpls traffic-eng

tunnel destination 10.30.254.14

tunnel mpls traffic-eng autoroute announce

tunnel mpls traffic-eng path-option 1 dynamic

tunnel mpls traffic-eng fast-reroute

router bgp 15735

template peer-policy iBGP-RRC-POLICY-TEMPLATE

  route-reflector-client

  advertisement-interval 0

  next-hop-self

  send-community both

exit-peer-policy

!

template peer-policy iBGP-POLICY-TEMPLATE

  advertisement-interval 0

  next-hop-self

  send-community both

exit-peer-policy

!

template peer-session iBGP-RRC-SESSION-TEMPLATE

  remote-as 15735

  description ***For-RR-Client-Peerings***

  update-source Loopback0

  version 4

  timers 30 90

exit-peer-session

!

template peer-session iBGP-SESSION-TEMPLATE

  remote-as 15735

  description ***For-Non-Client-Peerings***

  update-source Loopback0

  version 4

  timers 30 90

exit-peer-session

=================================

Device B:

interface Tunnel300

description ***B to A***

ip unnumbered Loopback0

tunnel mode mpls traffic-eng

tunnel destination 10.30.254.1

tunnel mpls traffic-eng autoroute announce

tunnel mpls traffic-eng path-option 1 dynamic

tunnel mpls traffic-eng fast-reroute

router bgp 15735

template peer-policy iBGP-POLICY-TEMPLATE

  advertisement-interval 0

  next-hop-self

  send-community both

exit-peer-policy

!

template peer-session iBGP-SESSION-TEMPLATE

  remote-as 15735

  description ***For-Non-Client-Peerings***

  update-source Loopback0

  version 4

  timers 30 90

exit-peer-session

[Muhammad Thanveer]

Hello,

Please cross check the below one's-------

Is the tunnel is up?

What is the igp you are using for traffic engineering?

are you able to ping the tunnels head end and tail end?

you have anounced a fast reroute, is there any backup tunnel? If yes from where is it initiated?

can you trace the loopbacks which you have used in traffic engineering, are they taking desired path?

Is your ldp session is properly built?

Is there any rsvp bandwidth reservation available on the interfaces?

If you are using IS-IS as an IGP, and if it is xr have you seen whether it is or not the proble with ingle topology and

have you done the metric-style wide and traffic engineering level 1 or 2 as per the requirement is done?

If it is ospf then, are all the prerequisties done?

Please post the full configurations, I think somebody can help you?

Regards
Thanveer
"Everybody is genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is a stupid."

[Alessio Andreoli]

Hi,
Please default the BGP timers and take out advertisement-interval 0 command. After that if it does not stabilise, debug the BGP updates between the two routers. What is the design? Can you share it?



Ps: community is to be extended if I am not wrong...


Regards,
Alessio

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[Kamini_24]

Hi,

Design attached, ambxwk1 is Device A and cmbmrs1 is Device B.

[Kamini_24]

[blau grana · Accepted solution]

Hello Kamini,

Problem could be MTU mismatch between both peers, can you verify IP MTU on both tunnel interfaces?

Try to set ip tcp adjust-mss 1300

If this help to stop flapping, problem will be with MTU.

Best Regards

Please rate all helpful posts and close solved questions

[Kamini_24]

Device B#show ip interface tunnel320

Tunnel320 is up, line protocol is up

Interface is unnumbered. Using address of Loopback0 (10.30.254.1)

Broadcast address is 255.255.255.255

MTU is 1596 bytes

Device A#show ip interface tunnel 300

Tunnel300 is up, line protocol is up

Interface is unnumbered. Using address of Loopback0 (10.30.254.14)

Broadcast address is 255.255.255.255

MTU is 9212 bytes

Yes, there is mtu mismatch, we tried to config manually but On Device A we couldn't configure ip mtu on the tunnel.

Device A is Cisco ME 3600

Device B is Cisco 7600

[blau grana]

Have you tried ip tcp adjust-mss 1300 on tunnnel interfaces, did it help?

Configuring MTU for metro 3600:

http://www.cisco.com/en/US/docs/switches/metro/me3600x_3800x/software/release/12.2_52_ey/configuration/guide/swint.html#wp1154596

Best Regards

Please rate all helpful posts and close solved questions

[Kamini_24]

Will try and getback, Thanks.

[paul driver]

Hello
Looks like BGP is flapping due to intermittent L2 connection loss- and the hold time has expired as the peers are not receiving any update or reply to the hellos they are sending

First check the physical interfaces for these routers (any errors?), also as suggested by others I would then check if any issue with L3 communication

apply an extended ping to the bgp peer and check the results

Res
paul


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