MPLS ICMP Extensions

Sun Aug 17 09:43:45 UTC 2003

As far as I remember we have seen labels from other providers, until 
they turned on the "traceroute hide". And there was no LDP coupling 
between them and us so ... . That was with Cisco in both networks.

The question is if these information cause any problem for you - 
despite curious customers asking ;-)

The labels seem to be allocated from a start value - usually 20, 1024, 
4096 or such, depending on your system, OS version - in an incremental 
order, so guessing labels isn't that difficult. If your network accepts 
labels although it shouldn't then the extra information in ICMP doesn't 
really make things worse anymore.

Marc

On Thursday, August 14, 2003, at 08:39  PM, Leo Bicknell wrote:

> In a message written on Thu, Aug 14, 2003 at 01:21:28PM -0500, Mike 
> Bernico wrote:
>> Maybe I'm wrong, but I thought that the extended MPLS info only showed
>> up when the trace was started on a PE or P router. Is that right?
>
> I did the traceroute from a router with _NO_ mpls commands turned on,
> and it's on a network that uses _NO_ mpls today.
>
> Basically from reading the draft if the router that generates the ICMP
> unreachable received the packet with an MPLS label, it adds the MPLS
> info to the returned data.  As long as your traceroute can parse/show
> it (so far I've only confirmed Juniper can do it), it will be displayed
> to the world.
>
> -- 
>        Leo Bicknell - bicknell at ufp.org - CCIE 3440
>         PGP keys at http://www.ufp.org/~bicknell/
> Read TMBG List - tmbg-list-request at tmbg.org, www.tmbg.org
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--
Marc Binderberger    <marc at sniff.de>    Powered by *BSD ;-)