I recently found myself in an interesting discussion regarding MPLS LDP. More specifically LDP identifiers, along with some interesting corner cases and caveats–depending on your IGP of choice and the scale of your network. I thought I’d write a post attempting to subjectively answer the following question.
Does LDP need an Identifier derived from an IPv4 address with a /32 network mask to work?
Considering the available label distribution protocols in MPLS networks, RSVP-TE and LDP are the de-facto standards. LDP is quite popular, however, one of its main limitations is the lack of traffic engineering support–ignoring CR-LDP for now. Sometimes even small networks can benefit from steering traffic one way or another to avoid potential congestion scenarios and/or underutilised links. This post looks at how LDP over RSVP-TE works in small Juniper MX core network deployment primarily running LDP as its main label distribution protocol.
When it comes to MPLS, undoubtedly virtual private network (VPN) is one of its most popular and successful applications. Any Transport over MPLS (AToM) or L2VPN as it’s sometimes referred to allows customers’ sites to be interconnected at a Layer 2 level over the carrier’s MPLS backbone whilst supporting numerous different access technologies such as Frame Relay, ATM, PPP and Ethernet. Although some of these are considered legacy and are rarely encountered in modern network deployments, they still exist in some production environments scattered across the globe.