Rsvp-Te Lsp Shortcut For Igp Resolution - Alcatel-Lucent 7450 Manual

Manager (TTM) and is available to applications such as LDP-over-RSVP, resolution of BGP label
routes, resolution of BGP, IGP, and static routes. It is, however, not available to be used as a
provisioned SDP for explicit binding or auto-binding by services.
If the one-hop option is specified instead of a prefix policy, this command enables the automatic
signaling of one-hop point-to-point LSPs using the specified template to all directly connected
neighbors. This LSP type is referred to as auto-LSP of type one-hop. Although the provisioning
model and CLI syntax differ from that of a mesh LSP only by the absence of a prefix list, the
actual behavior is quite different. When the above command is executed, the TE database will
keep track of each TE link that comes up to a directly connected IGP neighbor whose router-id is
discovered. It then instructs MPLS to signal 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 neighboring router.
An auto-created mesh or one-hop LSP can have egress statistics collected at the ingress LER by
adding the egress-statistics node configuration into the LSP template. The user can also have
ingress statistics collected at the egress LER using the same ingress-statistics node in CLI used
with a provisioned LSP. The user must specify the full LSP name as signaled by the ingress LER
in the RSVP session name field of the Session Attribute object in the received Path message.

RSVP-TE LSP Shortcut for IGP Resolution

RSVP-TE LSP shortcut for IGP route resolution allows forwarding of packets to IGP learned
routes using an RSVP-TE LSP. This is also referred to as IGP shortcut. This feature is enabled by
entering the following command at the IS-IS routing protocol level or at the OSPF routing
protocol instance level:
•
•
These commands instruct IS-IS or OSPF to include RSVP LSPs originating on this node and
terminating on the router-id of a remote node as direct links with a metric equal to the operational
metric provided by MPLS. If the user enabled the relative-metric option for this LSP, 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.
When a prefix is resolved to a tunnel next-hop, the packet is sent labeled with the label stack
corresponding to the NHLFE of the RSVP LSP. Any network event causing an RSVP LSP to go
down will trigger a full SPF computation which may result in installing a new route over another
RSVP LSP shortcut as tunnel next-hop or over a regular IP next-hop.
When rsvp-shortcut 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-
7450 ESS MPLS Guide
config>router>isis>rsvp-shortcut
config>router>ospf>rsvp-shortcut
MPLS and RSVP
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