190
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 do…
Use the command…
Remarks
Step 1
Enter system view
system-view
––
Step 2
Enter IS-IS view
isis
[
process-id
] [
vpn-instance
vpn-
instance-name
]
––
Step 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
] ]
Required
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.
To do…
Use the command…
Remarks
Step 1
Enter system view
system-view
––
Step 2
Enter IS-IS view
isis
[
process-id
] [
vpn-instance
vpn-
instance-name
]
––
Step 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
] *
Required
Disabled by
default
•
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.
