[j-nsp] Longest Match for LDP (RFC5283)

[James Bensley]

On 31 July 2018 at 15:29,  <adamv0025 at netconsultings.com> wrote:
> One follow up question,
> What about the case, where the minimum set of /32 loopback routes and associated labels is simply beyond the capabilities of an access node.
> Is there a possibility for such access node to rely on default route + label -where originator of such a labelled default-route is the local ABR(s) in "opt-B" role doing full IP lookup and then repackaging packets towards the actual NH please?

Hi Adam,

In the Seamless MPLS design the access nodes have a single default
route or single summary prefix for your loopback range (say
192.0.2.0/24) and use LDP Downstream on Demand and request the
transport labels from the aggregation nodes only for the remote PEs
the access node actually needs (i.e. where you have configured a
pseudowire/L2 VPN towards, iBGP neghbour address for L3 VPN etc.). So
the access node should *only* have exactly the labels it needs with a
single route (when using RFC5283).

Cheers,
James.