MPLS Label Distribution Protocol

Label Distribution Protocol (LDP) is a protocol that automatically generates and exchanges MPLS labels between routers. Each router will locally generate labels for its prefixes and will then advertise the label values to its neighbors.

Like many other protocols, LDP first establishes a neighbor adjacency before it exchanges label information.

An alternative to the use of LDP is the use of multiprotocol BGP. MP-BGP supports MPLS label distribution as well using BGP NLRIs.

https://networklessons.com/mpls/mpls-ldp-label-distribution-protocol