3Com Switch 8800 Family Configuration Guide

Configuring Integrated IS-IS 349
The default route generated by this command will only be imported to the router
at the same level.
Setting the Preference
of IS-IS Protocol
In a router on which several routing protocols are concurrently operating, there is
an issue of sharing and selecting the routing information among all the routing
protocols. The system sets a preference for each routing protocol. When various
routing protocols find the route to the same destination, the protocol with the
higher preference will take effect.
Perform the following configuration in IS-IS view.
By default, the preference of IS-IS route is 15.
Configuring IS-IS Route
Metric Type
IS-IS routing protocol has two styles of route metric:
■ Narrow: The value of route metric ranges from 1 to 63.
■ Wide: The value of route metric ranges from 1 to 16,777,215.
A router can choose either or both of the styles.
Perform the following configuration in IS-IS view.
By default, IS-IS only receives and sends the packets whose route metric is in
narrow style.
Setting IS-IS Link State
Routing Cost
Users can configure the interface cost, namely, the default routing cost.
Perform the following configuration in interface view.
If the level is not specified, the default setting is Level-1 routing cost.
The value argument is configured according to the link state of the interface.
By default, the routing cost of IS-IS on an interface is 10.
Tab le 320 Configure the preference of IS-IS protocol
Operation Command
Configure the preference of IS-IS protocol preference value
Restore the default preference of IS-IS protocol undo preference
Tab le 321 Configure the style for route metric values of IS-IS packets
Operation Command
Configure the style for route metric
values of IS-IS packets
cost-style { narrow | wide | wide-compatible | {
compatible | narrow-compatible } [ relax-spf-limit ] }
Restore the default settings undo cost-style
Tab le 322 Set IS-IS link state routing cost
Operation Command
Set the routing cost of the interface isis cost value [ level-1 | level-2 ]
Restore the default routing cost of the interface undo isis cost [ level-1 | level-2 ]