H3C Technologies H3C SR8800 - Manual (Page 172)

156
Configuring IS-IS route summarization
This task allows you to configure a summary route, so routes falling into the network range of the
summary route are summarized into one route for advertisement. Doing so can reduce the size of routing
tables, as well as the scale of LSP and LSDB. Both IS-IS routes and redistributed routes can be
summarized.
To configure route summarization:
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 IS-IS
route
summarization.
summary ip-address { mask | mask-length }
[ avoid-feedback | generate_null0_route |
tag tag | [ level-1 | level-1-2 | level-2 ] ] *
By default, no route summarization
is configured.
NOTE:
•
The cost of the summary route is the lowest one among the costs of summarized routes.
• The router summarizes only the routes in the locally generated LSPs.
Advertising a default route
A router running IS-IS cannot redistribute any default route or advertise a default route to neighbors. You
can use the following commands to advertise a default route of 0.0.0.0/0 to the same level neighbors.
To advertise a default route:
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. Advertise a default
route.
default-route-advertise [ route-policy
route-policy-name | [ level-1 | level-1-2 |
level-2 ] ] *
By default, the function is disabled.
NOTE:
The default route is only advertised to routers at the same level. You can use a routing policy to generate
the default route only when a local routing entry is matched by the policy.
Configuring IS-IS route redistribution
Redistributing large numbers of routes on a router may affect the performance of other routers in the
network. If this happens, you can configure a limit on the number of redistributed routes in order to limit
the number of routes to be advertised.
To configure IS-IS route redistribution from other routing protocols: