isis peer hold-cost timer

Function

The isis peer hold-cost command sets the period during which IS-IS keeps the specified cost in the Link State PDUs (LSPs) of the local device.

The undo isis peer hold-cost command restores the default setting.

By default, after a neighbor relationship is established, IS-IS does not retain the specified cost and hold time in local LSPs.

Format

isis peer hold-cost cost-val timer timer-val

undo isis peer hold-cost [ cost-val timer timer-val ]

Parameters

Parameter	Description	Value
timer timer-val	Specifies the interval for holding the cost.	The value is an integer in the range of 100-1000000, in milliseconds.
hold-cost cost-val	Specifies the hold cost.	Specifies the hold cost.

Parameter

Description

Value

timer timer-val

Specifies the interval for holding the cost.

The value is an integer in the range of 100-1000000, in milliseconds.

hold-cost cost-val

Specifies the hold cost.

Views

100GE interface view, 10GE interface view, 25GE sub-interface view, 25GE interface view, 400GE interface view, 40GE interface view, 50GE sub-interface view, 50GE interface view, Eth-Trunk interface view, FlexE interface view, GE optical interface view, GE electrical interface view, Global VE sub-interface view, Tunnel interface view, VBDIF interface view, VE sub-interface view, VE interface view, VLANIF interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
isis	write

Usage Guidelines

Usage Scenario

When an IS-IS interface changes from down to up, the IS-IS neighbor relationship is re-established. After IGP route convergence is completed, traffic is switched back to the recovered link. As IGP routes converge fast, many services that depend on IGP routes may require a delayed switchback. After the isis peer hold-cost command is run, the IS-IS LSP on the local device retains the specified cost for a period of time. In this manner, traffic is forwarded along the original path. After the hold-cost timer expires, the cost is restored to the normal value, and traffic is switched back normally.

For P2P neighbors and broadcast neighbors, the time for starting the hold-cost timer is as follows:

For a P2P neighbor, the hold-cost timer is started after the neighbor goes Up.
After a broadcast neighbor goes Up, a DIS is elected. After the DIS is elected successfully, the hold-cost timer is started.

Precautions

This command is valid for both IPv4 and IPv6. The maximum cost time of IPv4 and IPv6 on an interface is controlled by the same timer.

If both the isis peer hold-max-cost and isis peer hold-cost commands are run, the latest configuration overrides the previous one.

The isis peer-hold-cost and cost-style commands are not associated. After the isis peer-hold-cost command is run, the cost value calculated using the actual logic takes effect.

Example

# On Ethernet 0/1/16, set the period during which IS-IS keeps the cost value of 22 in LSPs sent by the local device to 100000 ms.

<HUAWEI> system-view
[~HUAWEI] interface Ethernet 0/1/16
[~HUAWEI-Ethernet0/1/16] isis enable
[*HUAWEI-Ethernet0/1/16] isis peer hold-cost 22 timer 100000