[j-nsp] MTU changes affecting BGP sessions

[Kevin Oberman]

> Date: Wed, 26 Jul 2006 13:45:02 -0300
> From: Raniery Pontes <raniery at rnp.br>
> Sender: juniper-nsp-bounces at puck.nether.net
> 
> 
> So far, I=B4ve got three things to investigate:
> 
> - "system internet-options path-mtu-discovery"  (I wasn=B4t using it)
> - pr 67373 (and maybe a JUNOS upgrade)
> - Adjust jumbo frames in every switch in the path
> 
> Much better than 4 hours ago ...

I believe that you stated that the interface MTU was set to 9000. It is
possibly worth noting that the IP MTU should really be 9000 and the
interface MTU should be at least 9022 to comply with the jumbo frame
size used on most internation R&E networks.
mtu 9022
family inet {
   mtu 9000;
   address xxx.yyy.zzz.aaa;
}
family inet6 {
    mtu 9000;
    address 2001:tttt::1/64;
}

If MPLS will be used, an even larger interface MTU may be needed. We set
our interface MTU to 9192 which is the maximum.
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634
Key fingerprint:059B 2DDF 031C 9BA3 14A4  EADA 927D EBB3 987B 3751