Automatic Creation of an SR-TE One-Hop LSP

This feature like the RSVP-TE auto-LSP using an LSP template of one-hop-p2p type. Although the provisioning model and CLI syntax differ from that of a mesh LSP by the absence of a prefix list, the actual behavior is quite different. When the one-hop-p2p command is executed, the TE database keeps track of each TE link that comes up to a directly connected IGP neighbor. It then instructs MPLS to instantiate an SR-TE LSP with the following parameters:

In this case, the hop-to-label translation or the local CSPF returns the SID for the adjacency to the remote address of the neighbor on this link. Therefore, the auto-lsp command binding an LSP template of type one-hop-p2p-srte with the one-hop option results in one SR-TE LSP instantiated to the IGP neighbor for each adjacency over any interface.

Because the local router installs the adjacency SID to a link independent of whether the neighbor is SR-capable, the TE-DB finds the adjacency SID and a one-hop SR-TE LSP can still come up to such a neighbor. However, remote LFA using the neighbor’s node SID will not protect the adjacency SID and so, will also not protect the one-hop SR-TE LSP because the node SID is not advertised by the neighbor.

The LSP has an auto-generated name using the following structure:

TemplateName-DestIpv4Address-TunnelId

where:

The path name is that of the default path specified in the LSP template.

Note: This feature is limited to an SR-TE LSP that is controlled by the router (PCC-controlled) and for which labels for the path are provided by the hop-to-label translation or the local CSPF path computation method.