Alcatel-Lucent 7450 Manual page 263

ldp-over-rsvp
Syntax ldp-over-rsvp [include | exclude]
Context config>router>mpls>lsp
Description
This command specifies if this LSP will be included in LDP over RSVP.
Parameters include — Specifies that this LSP will be included in LDP over RSVP.
exclude — Specifies that this LSP will be excluded from LDP over RSVP.
igp-shortcut
Syntax igp-shortcut [lfa-protect | lfa-only] [relative-metric [offset]]
[no] igp-shortcut
Context config>router>mpls>lsp
Description This command enables the use of a specific RSVP LSP by IS-IS and OSPF routing protocols as a
shortcut or as a forwarding adjacency for resolving IGP routes.
When the rsvp-shortcut or the advertise-tunnel-link option is enabled at the IGP instance level, all
RSVP LSPs originating on this node are eligible by default as long as the destination address of the
LSP, as configured in config>router>mpls>lsp>to, corresponds to a router-id of a remote node.
The lfa-protect option allows an LSP to be included in both the main SPF and the Loop-Free
Alternate (LFA) SPF. For a given prefix, the LSP can be used either as a primary next-hop or as an
LFA next-hop, but not both. If the main SPF computation selected a tunneled primary next-hop for a
prefix, the LFA SPF will not select an LFA next-hop for this prefix and the protection of this prefix
will rely on the RSVP LSP FRR protection. If the main SPF computation selected a direct primary
next-hop, then the LFA SPF will select an LFA next-hop for this prefix but will prefer a direct LFA
next-hop over a tunneled LFA next-hop.
The lfa-only option allows an LSP to be included in the LFA SPF only such that the introduction of
IGP shortcuts does not impact the main SPF decision. For a given prefix, the main SPF always selects
a direct primary next-hop. The LFA SPF will select a an LFA next-hop for this prefix but will prefer a
direct LFA next-hop over a tunneled LFA next-hop.
When the relative-metric option is enabled, IGP will apply the shortest IGP cost between the
endpoints of the LSP plus the value of the offset (instead of the LSP operational metric) when
computing the cost of a prefix which is resolved to the LSP. The offset value is optional and it
defaults to zero. The minimum net cost for a prefix is one (1) after applying the offset. Note that the
TTM continues the show the LSP operational metric as provided by MPLS. In other words,
applications such as LDP-over-RSVP (when IGP shortcut is disabled) and BGP and static route
shortcuts will continue to use the LSP operational metric.
The relative-metric option is mutually exclusive with the lfa-protect or the lfa-only options. In other
words, an LSP with the relative-metric option enabled cannot be included in the LFA SPF and vice-
versa when the rsvp-shortcut option is enabled in the IGP.
Finally, the relative-metric option is ignored when forwarding adjacency is enabled in IS-IS or
OSPF. In this case, IGP advertises the LSP as a point-to-point unnumbered link along with the LSP
7450 ESS MPLS Guide
MPLS and RSVP
Page 263