[c-nsp] BGP (VPNv4) flapping every 3minutes

Mark Tinka mark.tinka at seacom.mu
Sun Dec 21 01:57:25 EST 2014

On Sunday, December 21, 2014 01:28:30 AM CiscoNSP List 

> ok - Ive after a bit of searching, looks like it is
> caused by mtu...Ive added " transport path-mtu-discovery
> disable" to one of the RR's on .219, and it's been up
> for 7+min....looks like this was the issue..

To avoid this, I like to set "ip tcp-mss" (tcp-mss on Junos) 
to a fixed value lower than my core MTU, but high enough to 
ensure quick BGP updates are pushed out between routers.

This way, you don't end up with custom configurations like 
what you have above on some routers, and not on others, 
ensuring your configuration is pretty standard on all 

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 836 bytes
Desc: This is a digitally signed message part.
URL: <https://puck.nether.net/pipermail/cisco-nsp/attachments/20141221/c7f8174c/attachment.sig>

More information about the cisco-nsp mailing list