Login | Register For Free | Help
Search for: (Advanced)

Mailing List Archive: Cisco: NSP

traceroute shows mpls labels...how?

 

 

Cisco nsp RSS feed   Index | Next | Previous | View Threaded


aaron1 at gvtc

Aug 22, 2012, 12:21 PM

Post #1 of 14 (1593 views)
Permalink
traceroute shows mpls labels...how?

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 [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


roger.wiklund at gmail

Aug 22, 2012, 12:48 PM

Post #2 of 14 (1565 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

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 <aaron1 [at] gvtc> 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 [at] puck
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/

_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


aaron1 at gvtc

Aug 22, 2012, 12:53 PM

Post #3 of 14 (1570 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

Thanks Roger, I knew about that. But what I was asking is how does that
label information get reported back to the device that I'm doing the
traceroute from.... you see what I'm asking ?

I might put a sniffer on the device that I'm tracing from to look at that
icmp ttl expired in transit packets and see where exactly is that label
information embedded/carried in the ttl expired in transit packets..... see
what I'm asking ?

Aaron


-----Original Message-----
From: Roger Wiklund [mailto:roger.wiklund [at] gmail]
Sent: Wednesday, August 22, 2012 2:49 PM
To: Aaron
Cc: cisco-nsp [at] puck
Subject: Re: [c-nsp] traceroute shows mpls labels...how?

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 <aaron1 [at] gvtc> 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 [at] puck
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/

_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


philxor at gmail

Aug 22, 2012, 12:56 PM

Post #4 of 14 (1562 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

There are ICMP extensions to carry MPLS label stack information but the trace route application needs to support it. The windows client doesn't.

Phil

Sent from my iPad

On Aug 22, 2012, at 3:21 PM, "Aaron" <aaron1 [at] gvtc> 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 [at] puck
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/

_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


chrisccnpspam2 at gmail

Aug 22, 2012, 1:03 PM

Post #5 of 14 (1561 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

Also this depends on vendor too. IIRC junos uses udp for its trace routing
and ios uses icmp. Meaning that if you did traceroute from a cisco box
going over a juniper network the labels wouldn't show and vice versa. You
brought up something I was 100% suee about a few years ago but those brain
cells are gone.
On Aug 22, 2012 2:58 PM, "Phil Bedard" <philxor [at] gmail> wrote:

> There are ICMP extensions to carry MPLS label stack information but the
> trace route application needs to support it. The windows client doesn't.
>
> Phil
>
> Sent from my iPad
>
> On Aug 22, 2012, at 3:21 PM, "Aaron" <aaron1 [at] gvtc> 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 [at] puck
> > https://puck.nether.net/mailman/listinfo/cisco-nsp
> > archive at http://puck.nether.net/pipermail/cisco-nsp/
>
> _______________________________________________
> cisco-nsp mailing list cisco-nsp [at] puck
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
>
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


aaron1 at gvtc

Aug 22, 2012, 1:22 PM

Post #6 of 14 (1560 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

That's what I was looking for. So is it a part of the mpls lsr's icmp
implementation that would allow those icmp extensions to carry and send that
info or the traceing device (windows) or both? In other words, I wonder if
the windows device actually is rcv'ing the icmp extended packets carrying
that mpls label info BUT the tracert windows application just isn't smart
enough to render it on the cli output.. I would think that wireshark on
windows would tell me if it is or isn't seeing those extensions with the
label info



Aaron



From: Chris Evans [mailto:chrisccnpspam2 [at] gmail]
Sent: Wednesday, August 22, 2012 3:03 PM
To: Phil Bedard
Cc: &lt,cisco-nsp [at] puck&gt,; Aaron
Subject: Re: [c-nsp] traceroute shows mpls labels...how?



Also this depends on vendor too. IIRC junos uses udp for its trace routing
and ios uses icmp. Meaning that if you did traceroute from a cisco box
going over a juniper network the labels wouldn't show and vice versa. You
brought up something I was 100% suee about a few years ago but those brain
cells are gone.

On Aug 22, 2012 2:58 PM, "Phil Bedard" <philxor [at] gmail> wrote:

There are ICMP extensions to carry MPLS label stack information but the
trace route application needs to support it. The windows client doesn't.

Phil

Sent from my iPad

On Aug 22, 2012, at 3:21 PM, "Aaron" <aaron1 [at] gvtc> 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 [at] puck
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/

_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/

_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


philxor at gmail

Aug 22, 2012, 1:27 PM

Post #7 of 14 (1570 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

Yes wireshark should see the info. There are a couple rfcs for the extensions but I don't know what they are offhand. Does not require anything special in the client ICMP packet and only applies to TTL Exceeded and Dest Unreachable responses.

Phil

Sent from my iPad

On Aug 22, 2012, at 4:22 PM, "Aaron" <aaron1 [at] gvtc> wrote:

> That’s what I was looking for. So is it a part of the mpls lsr’s icmp implementation that would allow those icmp extensions to carry and send that info or the traceing device (windows) or both? In other words, I wonder if the windows device actually is rcv’ing the icmp extended packets carrying that mpls label info BUT the tracert windows application just isn’t smart enough to render it on the cli output…. I would think that wireshark on windows would tell me if it is or isn’t seeing those extensions with the label info
>
> Aaron
>
> From: Chris Evans [mailto:chrisccnpspam2 [at] gmail]
> Sent: Wednesday, August 22, 2012 3:03 PM
> To: Phil Bedard
> Cc: &lt,cisco-nsp [at] puck&gt,; Aaron
> Subject: Re: [c-nsp] traceroute shows mpls labels...how?
>
> Also this depends on vendor too. IIRC junos uses udp for its trace routing and ios uses icmp. Meaning that if you did traceroute from a cisco box going over a juniper network the labels wouldn't show and vice versa. You brought up something I was 100% suee about a few years ago but those brain cells are gone.
>
> On Aug 22, 2012 2:58 PM, "Phil Bedard" <philxor [at] gmail> wrote:
> There are ICMP extensions to carry MPLS label stack information but the trace route application needs to support it. The windows client doesn't.
>
> Phil
>
> Sent from my iPad
>
> On Aug 22, 2012, at 3:21 PM, "Aaron" <aaron1 [at] gvtc> 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 [at] puck
> > https://puck.nether.net/mailman/listinfo/cisco-nsp
> > archive at http://puck.nether.net/pipermail/cisco-nsp/
>
> _______________________________________________
> cisco-nsp mailing list cisco-nsp [at] puck
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


chrisccnpspam2 at gmail

Aug 22, 2012, 1:28 PM

Post #8 of 14 (1566 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

Yes the windows box will get, it just doesn't what to do with it. A router
that isn't mpls enabled, but can understand it will show them.
On Aug 22, 2012 3:22 PM, "Aaron" <aaron1 [at] gvtc> wrote:

> That’s what I was looking for. So is it a part of the mpls lsr’s icmp
> implementation that would allow those icmp extensions to carry and send
> that info or the traceing device (windows) or both? In other words, I
> wonder if the windows device actually is rcv’ing the icmp extended packets
> carrying that mpls label info BUT the tracert windows application just
> isn’t smart enough to render it on the cli output…. I would think that
> wireshark on windows would tell me if it is or isn’t seeing those
> extensions with the label info****
>
> ** **
>
> Aaron****
>
> ** **
>
> *From:* Chris Evans [mailto:chrisccnpspam2 [at] gmail]
> *Sent:* Wednesday, August 22, 2012 3:03 PM
> *To:* Phil Bedard
> *Cc:* &lt,cisco-nsp [at] puck&gt,; Aaron
> *Subject:* Re: [c-nsp] traceroute shows mpls labels...how?****
>
> ** **
>
> Also this depends on vendor too. IIRC junos uses udp for its trace
> routing and ios uses icmp. Meaning that if you did traceroute from a
> cisco box going over a juniper network the labels wouldn't show and vice
> versa. You brought up something I was 100% suee about a few years ago but
> those brain cells are gone. ****
>
> On Aug 22, 2012 2:58 PM, "Phil Bedard" <philxor [at] gmail> wrote:****
>
> There are ICMP extensions to carry MPLS label stack information but the
> trace route application needs to support it. The windows client doesn't.
>
> Phil
>
> Sent from my iPad
>
> On Aug 22, 2012, at 3:21 PM, "Aaron" <aaron1 [at] gvtc> 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 [at] puck
> > https://puck.nether.net/mailman/listinfo/cisco-nsp
> > archive at http://puck.nether.net/pipermail/cisco-nsp/
>
> _______________________________________________
> cisco-nsp mailing list cisco-nsp [at] puck
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/****
>
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


philxor at gmail

Aug 22, 2012, 1:28 PM

Post #9 of 14 (1567 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

Just the probe packets differ in protocol the responses are always ICMP responses.

Phil

Sent from my iPad

On Aug 22, 2012, at 4:03 PM, Chris Evans <chrisccnpspam2 [at] gmail> wrote:

> Also this depends on vendor too. IIRC junos uses udp for its trace routing and ios uses icmp. Meaning that if you did traceroute from a cisco box going over a juniper network the labels wouldn't show and vice versa. You brought up something I was 100% suee about a few years ago but those brain cells are gone.
>
> On Aug 22, 2012 2:58 PM, "Phil Bedard" <philxor [at] gmail> wrote:
> There are ICMP extensions to carry MPLS label stack information but the trace route application needs to support it. The windows client doesn't.
>
> Phil
>
> Sent from my iPad
>
> On Aug 22, 2012, at 3:21 PM, "Aaron" <aaron1 [at] gvtc> 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 [at] puck
> > https://puck.nether.net/mailman/listinfo/cisco-nsp
> > archive at http://puck.nether.net/pipermail/cisco-nsp/
>
> _______________________________________________
> cisco-nsp mailing list cisco-nsp [at] puck
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


sthaug at nethelp

Aug 22, 2012, 1:56 PM

Post #10 of 14 (1562 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

> Also this depends on vendor too. IIRC junos uses udp for its trace routing
> and ios uses icmp. Meaning that if you did traceroute from a cisco box
> going over a juniper network the labels wouldn't show and vice
> versa.

Works just fine, labels are shown, both ways in our mixed Cisco - Juniper
network.

Steinar Haug, Nethelp consulting, sthaug [at] nethelp
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


aaron1 at gvtc

Aug 22, 2012, 1:57 PM

Post #11 of 14 (1563 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

Chris/Phil, thanks a lot



Aaron



From: Phil Bedard [mailto:philxor [at] gmail]
Sent: Wednesday, August 22, 2012 3:29 PM
To: Chris Evans
Cc: &lt,cisco-nsp [at] puck&gt,; Aaron
Subject: Re: [c-nsp] traceroute shows mpls labels...how?



Just the probe packets differ in protocol the responses are always ICMP responses.



Phil

Sent from my iPad



On Aug 22, 2012, at 4:03 PM, Chris Evans <chrisccnpspam2 [at] gmail> wrote:

Also this depends on vendor too. IIRC junos uses udp for its trace routing and ios uses icmp. Meaning that if you did traceroute from a cisco box going over a juniper network the labels wouldn't show and vice versa. You brought up something I was 100% suee about a few years ago but those brain cells are gone.

On Aug 22, 2012 2:58 PM, "Phil Bedard" <philxor [at] gmail> wrote:

There are ICMP extensions to carry MPLS label stack information but the trace route application needs to support it. The windows client doesn't.

Phil

Sent from my iPad

On Aug 22, 2012, at 3:21 PM, "Aaron" <aaron1 [at] gvtc> 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 [at] puck
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/

_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/

_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


chrisccnpspam2 at gmail

Aug 22, 2012, 1:58 PM

Post #12 of 14 (1563 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

Ahh good. I can't exactly remember what I ran into. Thx for clearing that
up!
On Aug 22, 2012 3:56 PM, <sthaug [at] nethelp> wrote:

> > Also this depends on vendor too. IIRC junos uses udp for its trace
> routing
> > and ios uses icmp. Meaning that if you did traceroute from a cisco box
> > going over a juniper network the labels wouldn't show and vice
> > versa.
>
> Works just fine, labels are shown, both ways in our mixed Cisco - Juniper
> network.
>
> Steinar Haug, Nethelp consulting, sthaug [at] nethelp
>
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


sthaug at nethelp

Aug 22, 2012, 2:02 PM

Post #13 of 14 (1579 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

> That's what I was looking for. So is it a part of the mpls lsr's icmp
> implementation that would allow those icmp extensions to carry and send that
> info or the traceing device (windows) or both? In other words, I wonder if
> the windows device actually is rcv'ing the icmp extended packets carrying
> that mpls label info BUT the tracert windows application just isn't smart
> enough to render it on the cli output..

Since I get MPLS labels shown using "ntraceroute" (Nanog traceroute)
on my FreeBSD box, it's pretty clear that other hosts also receive
the MPLS label info (assuming it is transmitted by routers on the
way). Whether they can *use* the label info is another question.

Steinar Haug, Nethelp consulting, sthaug [at] nethelp
_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


bjorn at mork

Aug 23, 2012, 1:19 AM

Post #14 of 14 (1528 views)
Permalink
Re: traceroute shows mpls labels...how? [In reply to]

"Aaron" <aaron1 [at] gvtc> writes:

> 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?

See RFC4950


Bjørn

_______________________________________________
cisco-nsp mailing list cisco-nsp [at] puck
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/

Cisco nsp RSS feed   Index | Next | Previous | View Threaded
 
 


Interested in having your list archived? Contact Gossamer Threads
 
  Web Applications & Managed Hosting Powered by Gossamer Threads Inc.