Cisco Support Community
Community Member

MPLS inter-AS VPN (Option B ) issue

Hi All,

Please see the below network diagram.

Provivder 1 PE -----Provider 1 ABSR(NNI) -----    EBGP -----------Provider 2 ASBR ( NNI )   ----   -EBGP-------Provider 2 PE

We are facing one problem with this solution ie.Provider 2 ASBR is not allocating label for default route and it is allocation proper label for all the other prefixes. So customer can't able to use the default route.

Please help on this.

Thanks ,

Arun Mohan

Cisco Employee

MPLS inter-AS VPN (Option B ) issue

Hi Arun,

Have you tried the following:

R1(config)#mpls ip ? 

  default-route   Allow MPLS forwarding for ip default route

  propagate-ttl   Propagate IP TTL into the label stack

  ttl-expiration  Control MPLS TTL expiration behavior


R1(config)#mpls ip default-route


Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
Community Member

MPLS inter-AS VPN (Option B ) issue

Hi ,

I already tried mpls ip default route but it is not working.

Cisco Employee

MPLS inter-AS VPN (Option B ) issue

Hello Arun,

Not sure if I hae understood your prolem correctly. Does the solution include running "eBGP" P2 ASBR (NNI) and PE2? Shouldn't this be ibgp? Can you please confirm this. Second thing is if you are having a default route in the "core", my understanding is that you will see the label bindings in the control plane, but forwarding plane will actually show nothing. You can confirm this by this command:

show mpls ldp bindings

show mpls forwarding


CreatePlease to create content