Supported Platforms
LDP-synchronization
Syntax
Hierarchy Level
Release Information
Statement introduced in Junos OS Release 7.5.
Description
Enable synchronization by advertising the maximum cost metric until LDP is operational on the link.
LDP distributes labels in non-traffic-engineered applications. Labels are distributed along the best path determined by IS-IS. If the synchronization between LDP and IS-IS is lost, the label-switched path (LSP) goes down. Therefore, LDP and IS-IS synchronization is beneficial. When LDP synchronization is configured and when LDP is not fully operational on a given link (a session is not established and labels are not exchanged), IS-IS advertises the link with the maximum cost metric. The link is not preferred but remains in the network topology.
LDP synchronization is supported only on point-to-point interfaces and LAN interfaces configured as point-to-point interfaces under IS-IS. LDP synchronization is not supported during graceful restart.
To advertise the maximum cost metric until LDP is operational for LDP synchronization, include the ldp-synchronization statement.
To disable synchronization, include the disable statement. To configure the time period to advertise the maximum cost metric for a link that is not fully operational, include the hold-time statement.
 | Note: When an interface has been in the holddown state for more than 3 minutes, a system log message with a warning level is sent. This message appears in both the messages file and the trace file. |
The remaining statements are explained separately.
Required Privilege Level
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
