Context
The costs of IS-IS interfaces can be determined in the following modes in descending order by
priority:
l
Interface cost: is configured for a specified interface.
l
Global cost: is configured for all interfaces.
l
Automatically calculated cost: is automatically calculated based on the interface
bandwidth.
If none of the preceding configurations is performed, the default cost of an IS-IS interface is 10,
and the default cost style is narrow.
Procedure
l
Configure the IS-IS cost type.
1.
Run:
system-view
The system view is displayed.
2.
Run:
isis
[
process-id
]
The IS-IS view is displayed.
3.
Run:
cost-style
{
narrow
|
wide
|
wide-compatible
| { {
narrow-compatible
|
compatible
} [
relax-spf-limit
] } }
The IS-IS cost type is configured.
The cost range of an interface and a route received by the interface vary with the cost type.
–
If the cost type is narrow, the cost of an interface ranges from 1 to 63. The maximum
cost of a route received by the interface is 1023.
–
If the cost style is narrow-compatible or compatible, the cost of an interface ranges from
1 to 63. The cost of a received route is related to
relax-spf-limit
.
–
If
relax-spf-limit
is not specified, the cost of a route works as follows:
If the cost of a route is not greater than 1023 and the cost of every interface that the
route passes through is smaller than or equal to 63, the cost of the route received by
the interface is the actual cost.
If the cost of a route is not greater than 1023 but the costs of all interfaces that the
route passes through are greater than 63, the IS-IS device can learn only the routes
to the network segment where the interface resides and the routes imported by the
interface. The cost of the route received by the interface is the actual cost. Subsequent
routes forwarded by the interface are discarded.
If the cost of a route is greater than 1023, the IS-IS device can learn only the interface
whose route cost exceeds 1023 for the first time. That is, the cost of each interface
before this interface is not greater than 63. The routes of the network segment where
the interface resides and the routes imported by the interface can all be learned. The
cost of the route is 1023. Subsequent routes forwarded by the interface are discarded.
–
If
relax-spf-limit
is specified, the cost of a route works as follows:
S6700 Series Ethernet Switches
Configuration Guide - IP Routing
6 IS-IS Configuration
Issue 01 (2012-03-15)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
289
