Configuring Is-Is Route Filtering - H3C S5800 Series Configuration Manual

To do...
Redistribute routes from
another routing protocol
Configure the maximum
number of redistributed
Level 1/Level 2 IPv4
routes
Only active routes can be redistributed. You can use the display ip routing-table protocol command
to display route state information.

Configuring IS-IS Route Filtering

You can reference a configured ACL, IP prefix list or routing policy to filter routes calculated from the
received LSPs and the routes redistributed from other routing protocols.
Filtering routes calculated from received LSPs
IS-IS saves the LSPs received from neighbors in the LSDB, uses the SPF algorithm to calculate the
shortest path tree with itself as the root and installs the routes into the IS-IS routing table.
By reference a configured ACL, IP prefix list or routing policy, you can filter the calculated routes and
only the routes matching the filter can be added into the IS-IS routing table.
Follow these steps to filter routes calculated from received LSPs:
To do...
Enter system view
Enter IS-IS view
Filter routes calculated from
received LSPs
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.
Use the command...
import-route protocol [ process-id |
all-processes | allow-ibgp ] [ cost cost |
cost-type { external | internal } | [ level-1 |
level-1-2 | level-2 ] | route-policy
route-policy-name | tag tag ] *
import-route limit number
Use the command...
system-view
isis [ process-id ] [ vpn-instance
vpn-instance-name ]
filter-policy { acl-number | ip-prefix
ip-prefix-name | route-policy
route-policy-name } import
5-24
Remarks
Required
No route is redistributed by default.
If no level is specified, routes are
redistributed into the Level-2
routing table by default.
Optional
The number defaults to 16384.
Remarks
––
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Required
No filtering is configured by
default.