in mpls forwarding-tabe...

syjeon · ‎02-10-2008

I have a question about mpls forwarding-table in cisco devics

I created a l2 virtual circuit between 2 PE.

and I entered the command that show mpls forwardint-table.

and I counld see the like below

local lavel-40, outgoing-untagged l2ckt(401), next-hop point2point

Why L2ckt has no label?

in my thinking, It must be assigned label to switch to peer PE device

Edison Ortiz · ‎02-10-2008

You may need more routers to emulate MPLS. What you are seeing is a behavior called PHP (Penultimate Hop Popping) on which the label is popped off at the hop before the egress router.

http://www.juniper.net/techpubs/software/erx/junose72/swconfig-bgp-mpls/html/mpls-config5.html

HTH,

__

Edison.

syjeon · ‎02-10-2008

I know the PHP concept, But I wondered that why L2 ckt displayed no label in show mpls forwarding-table?

It is different no label(untagged) and pop tag(this mean that it works as PHP)

Edison Ortiz · ‎02-10-2008

Post configs and see if I can duplicate it.

__

Edison.