North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: BGP Session Timeout

  • From: Pascal Gloor
  • Date: Tue May 01 04:00:45 2007

Is it likely that BGP times out before underlying IP topology reconvergences
after a link/node failure? Do service providers ever set such low values of
BGP timeouts that BGP timeout will occur?

If not, what else may cause a BGP session to time out?

Depending on your hardware, you can trigger your BGP and IGP to shut sessions when the peer is gone.

On some cisco, you can have BFD (Bidirectional Forwarding Detection). you have to enable this on both sides. If BFD notices the peer is down, it will notify OSPF,BGP,... (if configured so).

for example:

interface GigabitEthernet0/0
 ip address
 bfd neighbor
 bfd interval 250 min_rx 250 multiplier 3
 ip ospf bfd

This will send a BFD packet every 250ms, expect one every 250ms and if 3 packets are missed (after 750ms) it will tell OSPF to shut any session towards (or routed via for the BGP case).


Attachment: smime.p7s
Description: S/MIME cryptographic signature