R2511-HP MSR Router Series Layer 3 - IP Routing Configuration Guide(V5)
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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 referencing a configured ACL, IP prefix list, or routing policy, you can filter the calculated routes. Only
the routes matching the filter can be added into the IS-IS routing table.
To filter routes calculated from received LSPs:
Ste
p
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. Filter routes calculated
from received LSPs.
filter-policy { acl-number | ip-prefix
ip-prefix-name | route-policy route-policy-name }
import
No filtering is configured by
default.
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:
Ste
p
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:
Ste
p
Command
Remarks
1. Enter system view.
system-view N/A