The ipv6 preference command sets a priority for the IPv6 routes generated by IS-IS.
The undo ipv6 preference command restores the default value.
By default, the priority for the IPv6 routes generated by IS-IS is 15.
| Parameter | Description | Value |
|---|---|---|
| route-policy route-policy-name |
Specifies the name of a route-policy. |
The name is a string of 1 to 200 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string. |
| route-filter route-filter-name |
Specifies the name of route filter policy. |
The value is a string of 1 to 200 case-sensitive characters, spaces not supported. If parameters are included in the referenced route-filter, specify values for them in the format of (var1, var2, ...var8) behind the route-filter name. A maximum of eight parameters can be specified, and each value ranges from 1 to 200 characters. |
| preference |
Specifies the priority. The smaller the value, the higher the priority. |
The value is an integer ranging from 1 to 255. |
Usage Scenario
Multiple dynamic routing protocols can be run on a device. In this case, set a default priority for each routing protocol. If different protocols have routes to the same destination, the route with the highest priority is selected for IP packet forwarding.
You can set a priority only for specific routes matching a route-policy. For the route that matches the route-policy, the priority set in the route-policy is preferred to the priority set using the ipv6 preference command. If no priority is set in the route-policy or the ipv6 preference command is not run, the default priority is used.Prerequisites
IPv6 has been enabled for the IS-IS process. For details, see isis ipv6 enable.