H3C Technologies H3C S12500 Series Switches - Manual (Page 169)

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Filtering redistributed routes
IS-IS can redistribute routes from other routing protocols or other IS-IS processes, add them into the IS-IS
routing table, and advertise them in LSPs.
By reference a configured ACL, IP prefix list, or routing policy, you can filter redistributed routes and only
the routes matching the filter can be added into the IS-IS routing table and advertised to neighbors.
To configure the filtering of redistributed routes:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter IS-IS view.
isis [ process-id ] [ vpn-instance
vpn-instance-name ]
N/A
3. Configure the filtering of
routes redistributed from
another routing protocol or
IS-IS process.
filter-policy { acl-number | ip-prefix
ip-prefix-name | route-policy
route-policy-name } export [ protocol
[ process-id ] ]
Not configured by
default.
Configuring IS-IS route leaking
With IS-IS route leaking enabled, the Level-1-2 router can advertise the routing information of other Level-1
areas and Level-2 area routing information to Level-1 routers.
If a filter policy is specified, only routes passing it can be advertised into Level-1 area.
You can specify a routing policy in the import-route isis level-2 into level-1 command to filter routes from
Level-2 to Level-1. Other routing policies specified for route reception and redistribution does not affect the
route leaking.
To configure IS-IS route leaking:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ] N/A
3. Enable IS-IS route
leaking.
import-route isis level-2 into level-1 [ filter-policy
{ acl-number | ip-prefix ip-prefix-name | route-policy
route-policy-name } | tag tag ] *
Disabled by
default.
Tuning and optimizing IS-IS networks
Configuration prerequisites
Before the configuration, complete the following tasks:
• Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
• Enable IS-IS.