Usage Scenario
By default, the cost type of IS-IS routes is narrow, which means that only routes with the cost ranging from 1 to 63 can be received and sent. LSPs carrying TE information when IS-IS is applied to MPLS TE or LSPs carrying tag information to be filtered by a route-policy cannot be flooded when the cost type is narrow. The cost-style command can be used to change the cost type of IS-IS routes so that they can be transmitted successfully.
To implement extended IS-IS functions, setting the cost type of IS-IS routes to wide is recommended.
The relax-spf-limit parameter is only valid when the overhead type is set to compatible and narrow-compatible.
Prerequisites
An IS-IS process has been created using the isis command.
Configuration Impact
When the cost type of a route is changed from wide to narrow, transmission of the route may be interrupted.
Precautions
If you want to change the cost type of IS-IS routes, running the command and configuring basic IS-IS functions is recommended. If the cost type of IS-IS routes is changed during network operation, the IS-IS process is restarted and neighbors are disconnected.
Before you enable TE for an IS-IS process, use the
cost-style command in IS-IS view to set the cost type of IS-IS packets to wide, compatible, or wide-compatible.