Riverstone Networks WICT1-12 17.2 ENABLING AND STARTING MPLS ON THE RS

Riverstone Networks RS Switch Router User Guide Release 8.0 17-11
MPLS Configuration Enabling and Starting MPLS on the RS
17.2 ENABLING AND STARTING MPLS ON THE RS
You must enable and start MPLS on all routers and all router interfaces that may become part of an LSP. You must
also enable and start either RSVP or LDP on the same routers and router interfaces2. When you enable MPLS and
either RSVP or LDP on the RS, MPLS uses RSVP or LDP to set up the configured LSPs. For example, when you
configure an LSP on the RS with both MPLS and RSVP running, RSVP initiates a session for the LSP. RSVP uses the
local router as the RSVP session sender and the LSP destination as the RSVP session receiver. When the RSVP session
is created, the LSP is set up on the path created by the session. If the session is not successfully created, RSVP notifies
MPLS; MPLS can then either initiate backup paths or retry the initial path.
Note For both RSVP and LDP, you must configure the router identifier on the LSR with
the ip-router global set router-id command.
The following CLI commands allow the RS to send and receive labeled packets:
In the above example, MPLS is enabled on the interfaces ‘int1’ and ‘int2’. Note that no MPLS processing occurs on
the router until MPLS is started with the mpls start command. This allows you to configure MPLS path
information, using other mpls commands, before starting MPLS.
LSRs can use RSVP to establish and maintain LSPs. As mentioned previously, RSVP is a protocol that allows channels
or paths to be reserved for specified transmissions. The following CLI commands enable RSVP on the RS:
2. You do not need to enable RSVP or LDP if you are configuring static LSPs. See Section17.5.1, "Config-
uring L3 Static LSPs."
! Enable MPLS on router interfaces
mpls add interface int1
mpls add interface int2
! Start MPLS on the router
mpls start
! Enable RSVP on router interfaces
rsvp add interface int1
! Start RSVP on the router
rsvp start