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Configuring route summarization on an ASBR
Perform this task to enable an ASBR to summarize external routes within the specified address
range into a single route. The ASBR advertises only the summary route to reduce the number of
LSAs in the LSDB.
An ASBR can summarize routes in the following LSAs:
Type-5 LSAs.
Type-7 LSAs in an NSSA area.
Type-5 LSAs translated by the ASBR (also an ABR) from Type-7 LSAs in an NSSA area.
If the ASBR (ABR) is not a translator, it cannot summarize routes in Type-5 LSAs translated
from Type-7 LSAs.
To configure route summarization on an ASBR:
1. Enter system view.
system-view
N/A
2. Enter OSPF view.
ospf
[
process-id |
router-id
router-id
|
vpn-instance
vpn-instance-name ]
*
N/A
3. Configure ASBR route
summarization.
asbr-summary
ip-address
{ mask-length | mask } [
cost
cost-value |
not-advertise
|
nssa-only
|
tag
tag ] *
By default, route summarization is
not configured on an ASBR.
Configuring received OSPF route filtering
Perform this task to filter routes calculated using received LSAs.
The following filtering methods are available:
Use an ACL or IP prefix list to filter routing information by destination address.
Use the gateway keyword to filter routing information by next hop.
Use an ACL or IP prefix list to filter routing information by destination address. At the same time
use the gateway keyword to filter routing information by next hop.
Use a routing policy to filter routing information.
To configure OSPF to filter routes calculated using received LSAs:
1. Enter system view.
system-view
N/A
2. Enter OSPF view.
ospf
[
process-id |
router-id
router-id |
vpn-instance
vpn-instance-name ] *
N/A
3. Configure OSPF to
filter routes
calculated using
received LSAs.
filter-policy
{ ipv4-acl-number [
gateway
prefix-list-name ] |
gateway
prefix-list-name
|
prefix-list
prefix-list-name [
gateway
prefix-list-name ] |
route-policy
route-policy-name }
import
By default, OSPF accepts all
routes calculated using received
LSAs.
Configuring Type-3 LSA filtering
Perform this task to filter Type-3 LSAs advertised to an area on an ABR.