- A virtual community of network engineers
 Home  BookStore  StudyNotes  Links  Archives  StudyRooms  HelpWanted  Discounts  Login
Confusion- MPLS Label Advertisement posted 09/01/2008
[Chronological Index] [Thread Index] [Top] [Date Prev][Date Next] [Thread Prev][Thread Next]

Hi Experts

I am sure someone will be able to answer my question.

The question
How can I make one of the interface advertise all the labels in MPLS ?
Given the situation its a  loopback interface.

Mpls ldp advertise-label interface loopback is not supported, though I can
type the command but it rejects it with the following error
"% Loopback interface is not supported"

Per the IETF documentation  (
The Loopback FEC type is defined to enable an upstream neighbor to
assist in the LSR self-testing at very low cost.  This FEC allows the
loopback to occur in the dataplane without control plane involvement beyond
the initial LDP exchange and dataplane setup.

An LSR uses the Loopback FEC to selectively advertise loopback labels    to
its neighbor LSRs.  Each loopback label is bound to a particular interface.
For multiaccess links, one label per neighbor is required since the
link-level address is derived from the label lookup.  When an MPLS packet
with its top label set to a loopback label is received from an interface
over which that label was advertised, the loopback label is popped and the
packet is sent on the interface to which the loopback label was bound.

Thanks in Advance

Warm Regards

Deepak Ahuja