MPLS TTL By default mpls ip propagation-ttl is enabled in global configuration mode. This enabled user to trace the hops of the mpls router with labels as shown in above traceroute. This is because MPLS TTL field is copied from IP TTL field, on each MPLS LSR hop a TTL will be decremented.
To “hide” the MPLS hops you can disable it by doing no mpls ip propagation-ttl on every LSR in global configuration mode. Disabling MPLS propagation TTL will make MPLS TTL field to have a fixed 255 value, and on every MPLS LSR hop the IP TTL value will be intact. IP TTL will only be decremented when egress LSR sends out to the destination host unlabeled. m1(config)#no mpls ip propagate-ttl Not sure why you're not seeing it in Windows, prob a very simple traceroute implementation. /Roger On Wed, Aug 22, 2012 at 9:21 PM, Aaron <aar...@gvtc.com> wrote: > Do you all know how this works? How is traceroute able to report back the > mpls label that is in use in the transit hops? Also wondering why I don't > see this on windows command line tracert > > > > Aaron > > > > > > RP/0/RSP0/CPU0:9k#trace vrf one 1.2.3.4 source 2.4.6.8 > > > > 1 19.1911.5 [MPLS: Labels 16001/16220 Exp 0] 2 msec 1 msec 0 msec > > 2 19.1911.1 [MPLS: Label 16220 Exp 0] 0 msec 0 msec 1 msec > > 3 88.88.191.22 0 msec 0 msec > > 19.1911.33 1 msec > > 4 88.88.191.18 1 msec 1 msec 0 msec > > 5 88.88.135.221 10 msec 10 msec 11 msec > > 6 122.47.236.130 [MPLS: Label 17039 Exp 1] 47 msec 49 msec 51 msec > > 7 122.47.154.53 [MPLS: Labels 0/17017 Exp 1] 48 msec 49 msec 47 msec > > 8 122.45.30.134 [MPLS: Labels 23417/17016 Exp 1] 48 msec 49 msec 47 msec > > 9 122.45.1.17 [MPLS: Labels 23439/17016 Exp 1] 50 msec 49 msec 51 msec > > 10 122.45.31.189 [MPLS: Labels 0/17016 Exp 1] 51 msec 54 msec 51 msec > > 11 122.45.158.34 [MPLS: Labels 0/16009 Exp 1] 49 msec 50 msec 47 msec > > 12 122.45.104.49 46 msec 46 msec 47 msec > > 13 122.45.108.14 47 msec 47 msec 47 msec > > 14 * * * > > 15 * * * > > 16 * > > > > _______________________________________________ > cisco-nsp mailing list cisco-nsp@puck.nether.net > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/