Alcatel-Lucent 7450 ESS Series, Руководство по настройке, Страница: 73 / 540

IP Router Configuration
7450 ESS OS Router Configuration Guide Page 73
Interaction with LDP Shortcut for Static Route Resolution
There is no interaction between LDP shortcut for static route resolution and the LDP shortcut for
IGP route resolution. A static route will continue to be resolved by searching an LDP LSP which
FEC prefix matches the specified indirect next-hop for the route. In contrast, the LDP shortcut for
IGP route resolution uses the LDP LSP as a route.
LDP Control Plane
In order for the LDP shortcut to be usable, a 7x50 must originate a <FEC, label> binding for each
IGP route it learns of even if it did not receive a binding from the next-hop for that route. In other
words, it must assume it is an egress LER for the FEC until the route disappears from the routing
table or the next-hop advertised a binding for the FEC prefix. In the latter case, the 7x50 becomes
a transit LSR for the FEC.
In the current TiMOS, a 7x50 will originate a <FEC, label> binding for its system interface
address only by default. The only way to originate a binding for local interfaces and routes which
are not local to the system is by using the fec-originate capability.
You must use the fec-originate command to generate bindings for all non-local routes for which
this node acts as an egress LER for the corresponding LDP FEC. Specifically, this feature must
support the FEC origination of IGP learned routes and subscriber/host routes statically configured
or dynamically learned over subscriber IES interfaces.
An LDP LSP used as a shortcut by IPv4 packets may also be tunneled using the LDP-over-RSVP
feature.