Directly connected PE routers? Is it possible?

So putting together a lab with the tiniest of MPLS cores: 2 PE routers.

Routes are advertised, but there seems to be something wrong with the data plane.  This typically tells me something is wrong with my LSP.  

I hop over to R1 (peers with R2 via the /32 loopback) and I do a traceroute to R2's loopback:


R1# sh ip cef

  nexthop GigabitEthernet1.46

I know that normally you'd see the transport label, but obviously we aren't seeing anything here.  

R1#sh mpls forwarding-table 

16         Pop Label       0             Gi1.46  



R4#sh mpls ldp bindings 

  lib entry:, rev 2

        local binding:  label: imp-null

        remote binding: lsr:, label: 16

  lib entry:, rev 4

        local binding:  label: 16

        remote binding: lsr:, label: imp-null


Does this look like a PHP issue?  Is it being popped prematurely? 


  • There is nothing wrong with back to back PEs. Just as long as the interface they are connected back to back against is running MPLS then you should have no issues. 

    The label stack will just contain the VPN label with no transport label. In your case is seems that R1 is routing to R4 to get to R2...what is the next hop of the VPN route? Is it 

    Can you show the output of 'sho mpls label bindins' on R1? 


  • Plucena,

    I'm not sure why I was having a problem to be honest.  I came back to it and I could ping across.  Good to know.  

Sign In or Register to comment.