Alcatel-Lucent 7450 Manual page 154

Automatic Creation of an RSVP One-Hop LSP
IGP neighbor which router-id is discovered. It then instructs MPLS to signals an LSP with a
destination address matching the router-id of the neighbor and with a strict hop consisting of the
address of the interface used by the TE link. Thus the auto-lsp command with the one-hop option
will result in one or more LSPs signaled to the IGP neighbor.
Only the router-id of the first IGP instance of the neighbor which advertises a TE link will cause
the LSP to be signaled. If subsequently another IGP instance with a different router-id advertises
the same TE link, no action is taken and the existing LSP is kept up. If the router-id originally used
disappears from the TE database, the LSP is kept up and is associated now with the other router-id.
The state of a one-hop LSP once signaled follows the following behavior:
•
•
•
All other feature behavior, limitations, and statistics support are the same as for an auto-LSP of
type mesh-p2p.
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If the interface used by the TE link goes down or BFD times out and the RSVP interface
registered with BFD, the LSP path moves to the bypass backup LSP if the primary path is
associated with one.
If while the one-hop LSP is UP, with the bypass backup path activated or not, the
association of the TE-link with a router-id is removed in the TE databases, the one-hop
LSP is torn down. This would be the case if the interface used by the TE link is deleted or
if the interface is shutdown in the context of RSVP.
If while the LSP is UP, with the bypass backup path activated or not, the TE database loses
the router-id, it will perform two separate updates to MPLS module. The first one updates
the loss of the TE link association which will cause action (B) above for the one-hop LSP.
The other update will state router-id is no longer in TE database which will cause MPLS
to tear down all mesh LSPs to this router-id as explained in Section 7.1.2. Note however
that a shutdown at the neighbor of the IGP instance which advertised the router-id will
cause the router-id to be removed from the ingress LER node immediately after the last
IGP adjacency is lost and is not subject to age-out as for a non-directly connected
destination router.
7450 ESS MPLS Guide