[c-nsp] RSVP-TE (MPLS-TE) and LDP question

[James Jun]

On Mon, May 11, 2020 at 01:02:23PM -0500, Aaron Gould wrote:
> Seems that when I try to use RSVP in place of LDP for label distribution, I
> cannot completely remove mpls ldp configs from IOS XR, but I can from IOS XE

It's an implementation 'bug' on IOS XR.

If you have L3VPN type service (also affects labeled-ucast, including 6PE), you *must*
have 'mpls ldp' and router-id configured at minimum, even if you are not using any LDP
adjacency whatsoever.  I believe ldp process needs to run to allocate labels for l3vpn,
even if you do not use LDP transport.

So, just leave 'mpls ldp' and router-id configured below it.  As long as you don't 
have LDP adjacencies defined, and there are no LDP tunnels configured, you won't have
any LDP in use.

P routers are not affected, as they do not need to allocate labels for VPN services.


James