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Configuring OSPF inbound route filtering
OSPF calculates routes by using LSAs. The calculated routes can be filtered and only permitted routes are
installed into the OSPF routing table.
OSPF provides the following filtering methods:
•
Filters routing information by destination address through ACLs and IP address prefixes
•
Filters routing information by next hop through the filtering criteria configured with the
gateway
keyword
•
Filters routing information by destination address through ACLs and IP address prefixes and by next
hop through the filtering criteria configured with the
gateway
keyword
•
Filters routing information by routing policy specified by the
route-policy
keyword
For more information about IP prefix list and routing policy, see "
To configure inbound route filtering:
Step Command
Remarks
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 inbound
route filtering.
filter-policy
{
acl-number
[
gateway
ip-prefix-name
] |
gateway
ip-prefix-name
|
ip-prefix
ip-prefix-name
[
gateway
ip-prefix-name
]
| route-policy
route-policy-name
}
import
Not configured by default.
Configuring ABR Type-3 LSA filtering
You can configure an ABR to filter Type-3 LSAs advertised to an area.
To configure Type-3 LSA filtering on an ABR:
Step Command
Remarks
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.
Enter area view.
area
area-id
N/A
4.
Configure ABR Type-3 LSA
filtering.
filter
{
acl-number
|
ip-prefix
ip-prefix-name
} {
import
|
export
}
Not configured by
default.
Configuring an OSPF cost for an interface
You can configure an OSPF cost for an interface by using either of the following methods:
•
Configure the cost value in interface view.
•
Configure a bandwidth reference value for the interface. OSPF computes the cost with this formula:
Interface OSPF cost = Bandwidth reference value (100 Mbps)/Interface bandwidth (Mbps). If the
