I seem to recall some odd MTU actions that routers will do if mpls is enabled and those actions differing depending on whether it was Ethernet or a serial link. I can't seem to nail down the specifics, my google-fu is failing. Something like the interface MTU increasing on a serial interface. Whereas the ipmtu decreasing on Ethernet interfaces.
--chip On Tuesday, January 15, 2013, Eric A Louie wrote: > No, the MTU was set to 1500. I have been informed that the tags create a > few > bytes of overhead that would cause problems in packets where DF was set. > But > even traffic that didn't traverse the mpls ip link was (seemingly) affected > > Much appreciated, Eric > > > > > ________________________________ > From: Oscar Belmar <[email protected] <javascript:;>> > To: Eric A Louie <[email protected] <javascript:;>> > Sent: Tue, January 15, 2013 4:45:57 PM > Subject: Re: [c-nsp] mpls ip creating traffic disturbance(s) > > > Did you change system or link MTU? > OBM > El 15/01/2013 21:27, "Eric A Louie" <[email protected] <javascript:;>> > escribió: > > We implemented what seemed to be a pretty simple mpls configuration to > test a > >vrf config. > > > >It caused widespread havoc across my production network. > > > >Has anyone encountered a situation where they've put "mpls ip" on a link > and > had > >it cause problems with web browsing to the Internet, even on traffic that > passed > >through the router that was not going through the mpls ip interfaces? > > > >I have a case open with Cisco TAC but was looking for some additional > guidance > >and perhaps some experience around this strange problem. > > > > Much appreciated, Eric > >_______________________________________________ > >cisco-nsp mailing list [email protected] <javascript:;> > >https://puck.nether.net/mailman/listinfo/cisco-nsp > >archive at http://puck.nether.net/pipermail/cisco-nsp/ > > > _______________________________________________ > cisco-nsp mailing list [email protected] <javascript:;> > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ > -- Just my $.02, your mileage may vary, batteries not included, etc.... _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
