[mpls-linux-general] About the Linux-MPLS tcpdump bug

[Daniel G. C. <da...@on...>]

Hi, I was wondering about the bug in Linux-MPLS that says that, when
you capture MPLS packets with Ethereal (tcpdump), if you run ethereal
on an LER the packets seem to be corrupted.

When I try with a 3 host network, (3---2---1) and I make ping
from one side to the other side of the net, packets (in one way) seem
to be corrupted, but in the other way don't. This is, for example,
from 1 to 3 they are ok, but from 3 to 1 they aren't MPLS packets.

And I am running ethereal in the LSR that is in the core of the
network (number 2) in spite of running it on an LER (3 or 1) so I
want to be sure that my problem is this bug and not a different one.
The packets captured in 2 don't seem to be corrupted, they are MPLS
packets in one way but in the other way they are normal IP packets
(non MPLS-packets).

Also, I have test it in a network like this 4--3--2--1 (four hosts) running
ethereal on 3 and 2, and the same problem happens. From 4 to 1 the sendings
are MPLS labelled IP packets, and from 1 to 4 the packets are normal IP
packets (non MPLS).

If you can confirm that my problem is the bug and not a different one I will
be so happy.

Thanks,Dani.