ipv6 circuit-cost

Function

The ipv6 circuit-cost command sets the cost value of all IPv6 interfaces in IS-IS SPF calculation, that is, the global IPv6 cost value.

The undo ipv6 circuit-cost command deletes the configured global IPv6 cost value.

By default, the global IPv6 cost value is not set.

Format

ipv6 circuit-cost { cost | maximum } [ level-1 | level-2 ]

undo ipv6 circuit-cost [ cost | maximum ] [ level-1 | level-2 ]

Parameters

Parameter	Description	Value
cost	Specifies the cost value of IPv6 interfaces in IS-IS SPF calculation.	IF the IS-IS cost style is wide or wide-compatible, the cost value of imported routes ranges from 1 to 16777214. Otherwise, the value ranges from 1 to 63.
maximum	Sets the link cost value of an interface to 16777215. NOTE: This parameter can be configured only when the IS-IS cost style is wide or wide-compatible. When the link cost value of an interface is set to 16777215, the neighbor TLV generated on the link cannot be used for route calculation and can only be used to transmit TE information.	-
level-1	Indicates the cost value of a Level-1 interface. If the interface level is not specified, the cost value is set for Level-1 and Level-2 interfaces.	-
level-2	Indicates the cost value of a Level-2 interface. If the interface level is not specified, the cost value is set for Level-1 and Level-2 interfaces.	-

Views

IS-IS view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

Generally, multiple valid routes to the same destination are available on large IPv6 networks. IS-IS calculates the optimal routes using SPF calculation and chooses the optimal routes for traffic forwarding. This process often causes the following two problems:

All the traffic is forwarded through the optimal route, which may cause unbalanced load.
If the optimal route on a network is disconnected intermittently, traffic is still forwarded through the optimal route, which causes traffic loss.

To solve the preceding problems, run the ipv6 circuit-cost command to change the cost value of all interfaces at a time and traffic can be forwarded through different physical links.

Precautions

The priority of the IPv6 cost value on the interface is higher than the priority of the global IPv6 cost value.

The ipv6 circuit-cost command can take effect only after IPv6 is enabled for the IS-IS process by the ipv6 enable command.

Example

# Set the global IPv6 cost value in SPF calculation to 20.

<HUAWEI> system-view

[HUAWEI] ipv6

[HUAWEI] isis 1

[HUAWEI-isis-1] ipv6 enable

[HUAWEI-isis-1] ipv6 circuit-cost 20