Turn on:
ip tcp path-mtu-discovery age-timer infinite
This will enable path-mtu-discovery for all TCP sessions (including BGP)
destined to or sourced from the router itself. It won't affect flows that
the router routes/switches.
-Brian
At 09:58 on 10/30/01, Loureiro, Rodrigo - (Bra) wrote:
> Hi Gert,
>
> Thanks in advance for response.
>
> >So your application should be able to handle everything from 1 byte to
> >4096 bytes - more than that is against the RFC, but your neighbors are
> >free to send up to that amount.
>
> This is linked to a fragmentation problem that i´m investigating with Cisco
> in PE routers (VPN/MPLS architecture). Actually, if i could guarantee that
> Cisco BGP´s implementation will not send a packet greater than 536 bytes, i
> could isolate the problem scope, once it will not affect my routing
> environment. However, if it follows RFC1771 in such a way that it is
> possible for Cisco´s peer to send a packet till 4096 bytes, than i should
> consider BGP inside the problem scope.
>
> I made a lab generating 2000 routes and than debugged the update packets
> between two MP-iBGP neighbors. I could see that BGP sends a lot of small
> packets, instead of aggregate a lot of NLRI´s in a single big packet.
> Actually, none of the packets observed reached 536 bytes.
>
> Based on the lab i could assume that BGP will not send datagrams greater
> than 536 bytes, but i could not get this information in any Cisco
> documentation, which means that i cannot guarantee this behaviour will be
> uniform.
>
> Do you have a pointer to any documentation that could solve my doubt ?
>
>
> Regards,
> --
>
> Rodrigo Loureiro
>
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:13:21 EDT