IS-IS SR-TE Client Mapping Advertisements

In an LDP network with gradual deployment of segment routing, there can be islands of devices that support either only LDP or only segment routing. To enable interoperability between the LDP devices and the segment routing devices, this feature introduces support for the LDP mapping client. The LDP mapping client advertises segment routing node SIDs and prefix SIDs - selected by the LDP egress policy - from a segment routing domain as LDP forwarding equivalence class (FEC) label bindings into the LDP domain. These LDP bindings are propagated across the LDP domain using classical LDP propagation mechanisms and installed by LDP-capable routers in the MPLS data plane exactly like classical LDP label bindings.