Weird MPLS Label Switching Problem

Hi,

I was studying MPLS VPN and while working on an example I am facing some
strange issue

The connectivity is CE1 - PE1 - P1 - P2 - PE2 - CE2

PE1(.1) - CE1 (.2) with subnet 172.16.1.0/24 with VRF A (RD=RT=1:1)
PE2(.1) - CE2 (.2) with subnet 172.16.2.0/24 with VRF A (RD=RT=1:1)

PE1 & PE2 have MPLS VPN set up and I can see labels for everything when I
check "show mpls forwarding" on the PEs

when I trace from PE1 to CE2 I can see labels being switches properly using
the following command
trace vrf A 172.16.2.2 source 172.16.1.1

but when trace from CE1 to CE2, there are no labels whatsoever
trace 172.16.2.2 source 172.16.1.2

Same thing is happening in the reverse direction (i.e. trace from CE2 to
CE1). I have done several examples previously and never faced such issue.
Instead of doing it all over again I want to troubleshoot the problem for
learning purpose

Can anybody suggest how to troubleshoot this problem? I have applied "no
mpls ip propagate-ttl" just to see if it was working and it worked

Please advise what should I do?

Thanks,
Malik

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Received on Sun Feb 27 2011 - 00:07:32 ART