1-20
Configuring IS-IS Route Summarization
This task is 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.
Follow these steps to configure route summarization:
To do…
Use the command...
Remarks
Enter system view
system-view
—
Enter IS-IS view
isis
[
process-id
] [
vpn-instance
vpn-instance-name
]
––
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
] ] *
Required
No route summarization is
configured by default.
z
The cost of the summary route is the lowest one among the costs of summarized routes.
z
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 and thus cannot advertise a default route to
other neighbors. You can use the following commands to advertise a default route of 0.0.0.0/0 to the
same level neighbors.
Follow these steps to advertise a default route:
To do…
Use the command…
Remarks
Enter system view
system-view
––
Enter IS-IS view
isis
[
process-id
] [
vpn-instance
vpn-instance-name
]
—
Advertise a default
route
default-route-advertise
[
route-policy
route-policy-name
| [
level-1
|
level-2
|
level-1-2
] ] *
Required
The function is disabled by
default.
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.
