Description

Steps to configure "strict-targeted-hellos" for LDP

Symptoms

If the LDP neighbor & interface are not defined, then "strict-targeted-hellos" will not work. 

When defining the LDP interface, use the "lo" interface with an IP.  If you don't, then define the LDP transport-address because the router uses the "lo" interface to establish the neighbor.

If you want to use physical interface, then define the interface and its IP address as the transport-address.

Solution

Below are the steps to configure "strict-targeted-hellos":

  1. Enable MPLS on the interface which will be used for establishing LDP neighbor.
  2. Under LDP, define neighbor. The option neighbor is hidden.
  3. Under LDP, define Interface used establish LDP neighbor.
  4. Under LDP, define the “transport-address” which should be the IP address of the above interface.
  5. Under LDP, enable “strict-targeted-hellos”.
  6. Configure the “targeted-hellos” parameters.
  7. Configure the peer end.
For example, the LDP configuration based on the ge-0/0/2 interface is as follows:

LDP Configuration:
s et protocols ldp strict-targeted-hellos
set protocols ldp transport-address 10.89.224.21
set protocols ldp interface ge-0/0/2.0
set protocols ldp neighbor 10.89.224.22
set protocols ldp targeted-hello hello-interval 3
set protocols ldp targeted-hello hold-time 10
Interface Configuration:
set interfaces ge-0/0/2 unit 0 family inet address 10.89.224.21/28
set interfaces ge-0/0/2 unit 0 family mpls
Similar configuration has to be done on the peer.