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 setting.

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.

Select parameters based on networking requirements:

If an IGP carries only LDP services, configure the parameter infinite to ensure that a selected IGP route is kept consistent with the LDP LSP.
If an IGP carries multiple types of services including LDP services, set the value of the parameter interval to ensure that a teardown of LDP sessions does not affect IGP route selection or other services.

Precautions

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.
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 IS-IS to keep advertising the maximum cost by sending Link State PDUs until the LSP is established.

<HUAWEI> system-view
[HUAWEI] isis 100
[HUAWEI-isis-100] timer ldp-sync hold-max-cost infinite