(Optional) Setting a Value for the Hold-down Timer

This section describes how to set a value for the hold-down timer. Before the timer expires, an interface waits for the setup of an LDP session and an LDP adjacency without setting up an IGP neighbor relationship.

Context

On a device that has LDP-IGP synchronization enabled, if the active physical link recovers, an IGP enters the Hold-down state, and a Hold-down timer starts. Before the Hold-down timer expires, the IGP delays establishing an IGP neighbor relationship until an LDP session and an LDP adjacency are reestablished over the active link so that the LDP session over and IGP route for the active link can become available simultaneously.

A Hold-down timer can be set on either an OSPF or IS-IS interface and can only be set in an IS-IS process, not in an OSPF process.

If different Hold-down values on an interface and in an IS-IS process are set, the setting on the interface takes effect.

Procedure

Set a value for the Hold-down timer on a specified OSPF interface:
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The interface view is displayed.
3. Run ospf timer ldp-sync hold-down value
  A value is set for the Hold-down timer, which enables an OSPF interface to delay establishing an OSPF neighbor relationship until an LDP session and an LDP adjacency are reestablished.
  
  To configure a value for the Hold-down timer on an OSPF multi-area adjacency interface, run the ospf timer ldp-sync hold-down value multi-area area-id command.
4. Run commit
  The configuration is committed.
Set a value for the Hold-down timer on a specified IS-IS interface:
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The interface view is displayed.
3. Run isis timer ldp-sync hold-down value
  A value is set for the Hold-down timer, which enables an IS-IS interface to delay establishing an IS-IS neighbor relationship until an LDP session and an LDP adjacency are reestablished.
4. Run commit
  The configuration is committed.
Set a value for the Hold-down timer on all IS-IS interfaces in a specified IS-IS process:
1. Run system-view
  The system view is displayed.
2. Run isis [ process-id ]
  The IS-IS process view is displayed.
3. Run timer ldp-sync hold-down value
  A value is set for the Hold-down timer, which enables all IS-IS interfaces within an IS-IS process to delay establishing IS-IS neighbor relationships until LDP sessions and LDP adjacencies are established.
4. Run commit
  The configuration is committed.