Gert, maybe you are hitting some old bug as I did long time ago on SXH1, it was 3C bug... http://www.gossamer-threads.com/lists/cisco/nsp/81589 ?
Best Regards, -mat On 9 March 2010 14:44, Gert Doering <[email protected]> wrote: > Hi, > > maybe a stupid question: are there any issues known with Rapid-PVSTP, > EoMPLS links, and IOS SXI2? > > We just had a "nice" problem due to a broadcast loop which should have > been broken by STP in the first place, but wasn't - and investigation > afterwards showed an EoMPLS link that just refuses to forward STP packets. > > Here's the setup (simplified): > > R1 ==(trunk)== R2 --(MPLS cloud)-- R3 ==(trunk)== R4 > > the trunk carries about 100+ VLANs, so R2 and R3 are setup to do > port-mode EoMPLS: > > interface GigabitEthernet2/21 > mtu 1504 > no ip address > udld port disable > xconnect 1.2.3.68 11310002 encapsulation mpls > end > > > Spanning-Tree is active, because of redundancy requirements - the connection > between R1 and R4 must not fail if R2 or R3 fail. So there is a second > trunk, and second EoMPLS link (not shown above). > > > What I can see when I do "show spanning-tree vlan 2800" on R1, it > claims "this bridge is the root" - and if I ask R4, R4 also claims > "this bridge is the root". If I flap the trunk link, I see both sides > go through the standard STP cycle (blocking/learning/forwarding), but > no rapid-STP exchange takes place. > > We have a number of similar links in our network, and never experienced > any problem with STP over port-mode EoMPLS (nor with STP over subif > EoMPLS either). The only thing that's unique about this particular link > is that "R3" is running SXI2, and all other (working) EoMPLS things are on > SXH3a, SXI, or SXI2a. > > > I'll open a TAC case for this, of course, but if one of you has come > across that and knows which IOS versions are problematic, that would > be appreciated. > > (NB: if one of you has a better suggestion to do "redundant trunks for > about 100-200 VLANs between R1 and R4" that does not require STP, let > me know. "Routed" link redundancy is not possible, as there are devices > to the left and right of R1 and R4 that need to be in the same L2 domain. > Depending on link state of R1->R2 is also not good enough, as R2 might > have some issues leading to end-to-end failure...) > > gert > -- > USENET is *not* the non-clickable part of WWW! > //www.muc.de/~gert/ > Gert Doering - Munich, Germany [email protected] > fax: +49-89-35655025 [email protected] > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
