timer ldp-sync hold-max-cost

Function

The timer ldp-sync hold-max-cost command sets the Hold-max-cost time during which all interfaces enabled with synchronization between LDP and IS-IS advertise link state PDUs (LSPs) carrying the maximum route cost.

The undo timer ldp-sync hold-max-cost command restores the default Hold-max-cost time.

The default Hold-max-cost time is 10 seconds.

Format

timer ldp-sync hold-max-cost { infinite | interval }

undo timer ldp-sync hold-max-cost

Parameters

Parameter	Description	Value
infinite	Enables IS-IS to advertise LSPs carrying the maximum route cost before LDP sessions are reestablished.	-
interval	Specifies the Hold-max-cost time during which IS-IS advertises LSPs carrying the maximum route cost on a local device.	The value is an integer ranging from 0 to 65535, in seconds.

Views

IS-IS view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

After synchronization between LDP and IS-IS is enabled, if the LDP session over the active link fails but the IS-IS route for the active link is reachable, IS-IS advertises the LSPs carrying the maximum route cost so that the IS-IS route and LDP session over a standby link can become reachable at the same time.

To set the Hold-max-cost time, run the timer ldp-sync hold-max-cost command.

Either of the following parameters can be configured in this command:

infinite: indicates that an IS-IS interface keeps advertising LSPs carrying the maximum cost value until an LDP session is established. This parameter ensures that the IS-IS route selects the same path over which an LDP LSP is established when an IS-IS network carries only LDP services.
interval: specifies the period of time during which an IS-IS interface keeps advertising LSPs carrying the maximum cost value. This parameter helps prevent an LDP session disconnection from affecting IS-IS routing or non-LDP services when an IS-IS network carries various services, including LDP services.

Configuration Impact

If the timer ldp-sync hold-max-cost infinite command is executed and the LDP session is Down, interfaces enabled with LDP and IS-IS synchronization keep advertising LSPs carrying the maximum route cost, which affects IS-IS routing.

Precautions

If both the timer ldp-sync hold-max-cost command and the isis timer ldp-sync hold-max-cost command in the interface view are executed, the isis timer ldp-sync hold-max-cost command takes effect.

Example

# Configure all interfaces enabled with synchronization between LDP and IS-IS to always keep advertising LSPs carrying the maximum route cost before LDP sessions are established.

<sysname> system-view

[sysname] isis 100

[sysname-isis-100] timer ldp-sync hold-max-cost infinite