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Verify the RSVP Protocol

 

Purpose

If the RSVP protocol is not enabled on the routers in your network, the interface cannot signal LSPs.

Action

To verify that the RSVP protocol is enabled, enter the following Junos OS CLI command:

Sample Output

Meaning

The sample output shows that the RSVP protocol is enabled on R1. The supported RSVP protocol is version 1, as defined in RFC 2205.

The RSVP refresh timer is set to 30 seconds, indicating that every 30 seconds, plus or minus 50 percent, the router will refresh the RSVP state with its directly connected neighbors by sending either a Path or a Resv message. The variable refresh time helps prevent harmonic oscillations in network traffic caused by periodic protocol updates.

The keepalive multiplier, K(keep multiplier), is input to a formula that helps determine the lifetime of an RSVP session. The session lifetime is reset each time the state is updated. The lifetime represents the duration of an RSVP session that does not receive any state updates (Path or Resv messages). The formula is:

RSVP session lifetime = (keep-multiplier + 0.5) * 1.5 * refresh-time

The RSVP preemption state is currently configured for normal preemption, indicating that only an LSP with a stronger priority can preempt an existing session; that is, the setup value of the new LSP is lower than the hold value of the existing LSP. Other options include aggressive preemption, which always preempts when there is insufficient bandwidth, and disabled, which prevents any preemption, regardless of LSP priority values.

Graceful restart is currently disabled and Restart helper mode is enabled. There are four combinations for Graceful restart and restart helper mode:

  1. Both Graceful restart and Restart helper mode are enabled.

  2. Graceful restart is enabled but Restart helper mode is disabled. An LSR with this configuration can restart gracefully but cannot help a neighbor with its restart and recovery procedures.

  3. Graceful restart is disabled but Restart helper mode is enabled. An LSR with this configuration can only help a restarting neighbor. It cannot restart gracefully itself.

  4. Graceful restart and Restart helper mode are both disabled. This configuration completely disables RSVP graceful restart (including restart and recovery procedures and helper mode). It is the same as an LSR that is not supported by RSVP graceful restart.

Restart time is the estimated time (in milliseconds) for an LSR to restart the RSVP traffic engineering component. In the example output, the restart time is 0 milliseconds, indicating that it is disabled.

The output is identical for all routers in the network shown in MPLS Network Topology.