[j-nsp] traceroute in mpls vpn's not showing P hops

Fri Aug 25 08:35:49 EDT 2017

I think there is a bug with logical tunnels with how it handles TTL. Try
physical ports for your logical systems.

On Fri, Aug 25, 2017 at 8:00 AM, Aaron Gould <aaron1 at gvtc.com> wrote:

> This is crazy… I was shutting down some lt interfaces trying to see if I
> could get traffic to follow that same path via where I saw the p hops
> reported on traceroute, and I suddenly saw it start working again where it
> will now show the p hops on traceroute, but a different path this time.
> I’m encouraged that p hops are seen on traceroute even via a different path
> then my previous email showed.  But weird that it works sometimes and not
> other times.  Not sure why yet.
>
>
>
>
>
> r1 at lab-mx104:r1> traceroute 1.1.10.2 wait 1
>
> traceroute to 1.1.10.2 (1.1.10.2), 30 hops max, 40 byte packets
>
> 1  1.1.0.2 (1.1.0.2)  0.537 ms  0.452 ms  0.359 ms
>
> 2  * * *
>
> 3  * * *
>
> 4  * * *
>
> 5  1.1.10.1 (1.1.10.1)  0.628 ms  0.629 ms  0.527 ms
>
> 6  1.1.10.2 (1.1.10.2)  0.580 ms  0.620 ms  0.542 ms
>
>
>
> r1 at lab-mx104:r1> traceroute 1.1.10.2 wait 1
>
> traceroute to 1.1.10.2 (1.1.10.2), 30 hops max, 40 byte packets
>
> 1  1.1.0.2 (1.1.0.2)  0.493 ms  0.471 ms  0.366 ms
>
> 2  * * *
>
> 3  * * *
>
> 4  * * *
>
> 5  1.1.10.1 (1.1.10.1)  0.686 ms  0.613 ms  0.523 ms
>
> 6  1.1.10.2 (1.1.10.2)  0.600 ms  0.587 ms  0.555 ms
>
>
>
> r1 at lab-mx104:r1> ping 1.1.10.2
>
> PING 1.1.10.2 (1.1.10.2): 56 data bytes
>
> 64 bytes from 1.1.10.2: icmp_seq=0 ttl=59 time=0.705 ms
>
> 64 bytes from 1.1.10.2: icmp_seq=1 ttl=59 time=0.769 ms
>
> 64 bytes from 1.1.10.2: icmp_seq=2 ttl=59 time=0.645 ms
>
> 64 bytes from 1.1.10.2: icmp_seq=3 ttl=59 time=0.638 ms
>
> 64 bytes from 1.1.10.2: icmp_seq=4 ttl=59 time=0.615 ms
>
> ^C
>
> --- 1.1.10.2 ping statistics ---
>
> 5 packets transmitted, 5 packets received, 0% packet loss
>
> round-trip min/avg/max/stddev = 0.615/0.674/0.769/0.056 ms
>
>
>
> r1 at lab-mx104:r1> traceroute 1.1.10.2 wait 1
>
> traceroute to 1.1.10.2 (1.1.10.2), 30 hops max, 40 byte packets
>
> 1  1.1.0.2 (1.1.0.2)  23.530 ms  0.403 ms  0.364 ms
>
> 2  1.1.7.2 (1.1.7.2)  0.679 ms  0.586 ms  1.884 ms
>
>      MPLS Label=300208 CoS=0 TTL=1 S=0
>
>      MPLS Label=16 CoS=0 TTL=1 S=1
>
> 3  1.1.11.2 (1.1.11.2)  1.481 ms  0.656 ms  0.627 ms
>
>      MPLS Label=300272 CoS=0 TTL=1 S=0
>
>      MPLS Label=16 CoS=0 TTL=2 S=1
>
> 4  1.1.6.1 (1.1.6.1)  0.628 ms  0.745 ms  0.640 ms
>
>      MPLS Label=300464 CoS=0 TTL=1 S=0
>
>      MPLS Label=16 CoS=0 TTL=3 S=1
>
> 5  1.1.2.2 (1.1.2.2)  0.704 ms  0.648 ms  0.633 ms
>
>      MPLS Label=300400 CoS=0 TTL=1 S=0
>
>      MPLS Label=16 CoS=0 TTL=4 S=1
>
> 6  1.1.3.2 (1.1.3.2)  0.662 ms  0.673 ms  0.683 ms
>
>      MPLS Label=300528 CoS=0 TTL=1 S=0
>
>      MPLS Label=16 CoS=0 TTL=5 S=1
>
> 7  1.1.10.1 (1.1.10.1)  0.662 ms  0.627 ms  0.669 ms
>
> 8  1.1.10.2 (1.1.10.2)  0.713 ms  0.673 ms  0.639 ms
>
>
>
> r1 at lab-mx104:r1>
>
>
>
> here’s some traces from the ingress PE r2…  the first trace is from
> ingress/egress pe’s r2 and r8 loopbacks… the second trace is from the pe/ce
> interface on r2/r8 facing their respective ce r1/r9…
>
>
>
>
>
> [edit]
>
> r2 at lab-mx104:r2# run traceroute 1.1.255.8 source 1.1.255.2
>
> traceroute to 1.1.255.8 (1.1.255.8) from 1.1.255.2, 30 hops max, 40 byte
> packets
>
> 1  1.1.7.2 (1.1.7.2)  0.734 ms  0.495 ms  0.381 ms
>
> 2  1.1.11.2 (1.1.11.2)  0.397 ms  0.532 ms  0.375 ms
>
> 3  1.1.255.8 (1.1.255.8)  0.564 ms  0.788 ms  0.535 ms
>
>
>
> [edit]
>
> r2 at lab-mx104:r2# run traceroute 1.1.10.1 source 1.1.0.2 routing-instance
> test
>
> traceroute to 1.1.10.1 (1.1.10.1) from 1.1.0.2, 30 hops max, 40 byte
> packets
>
> 1  1.1.7.2 (1.1.7.2)  0.722 ms  0.695 ms  0.596 ms
>
>      MPLS Label=300208 CoS=0 TTL=1 S=0
>
>      MPLS Label=16 CoS=0 TTL=1 S=1
>
> 2  1.1.11.2 (1.1.11.2)  0.588 ms  0.560 ms  0.528 ms
>
>      MPLS Label=300272 CoS=0 TTL=1 S=0
>
>      MPLS Label=16 CoS=0 TTL=2 S=1
>
> 3  1.1.6.1 (1.1.6.1)  0.617 ms  0.744 ms  0.623 ms
>
>      MPLS Label=300464 CoS=0 TTL=1 S=0
>
>      MPLS Label=16 CoS=0 TTL=3 S=1
>
> 4  1.1.2.2 (1.1.2.2)  0.696 ms  0.718 ms  0.629 ms
>
>      MPLS Label=300400 CoS=0 TTL=1 S=0
>
>      MPLS Label=16 CoS=0 TTL=4 S=1
>
> 5  1.1.3.2 (1.1.3.2)  0.647 ms  0.652 ms  0.628 ms
>
>      MPLS Label=300528 CoS=0 TTL=1 S=0
>
>      MPLS Label=16 CoS=0 TTL=5 S=1
>
> 6  1.1.10.1 (1.1.10.1)  0.798 ms  0.712 ms  0.667 ms
>
>
>
> [edit]
>
> r2 at lab-mx104:r2#
>
>
>
> - Aaron Gould
>
>
>