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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 and 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:
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 OSPF to
filter routes calculated
using received LSAs.
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
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.
To configure Type-3 LSA 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.
Enter area view.
area
area-id
N/A
4.
Configure Type-3 LSA
filtering.
filter
{
acl-number
|
ip-prefix
ip-prefix-name
} {
import
|
export
}
By default, the ABR does
not filter Type-3 LSAs.
Configuring an OSPF cost for an interface
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) / Expected interface bandwidth
(Mbps). The expected bandwidth of an interface is configured with the
bandwidth
command (see
Interface Command Reference
). If the calculated cost is greater than 65535, the value of 65535 is
used. If the calculated cost is less than 1, the value of 1 is used. If no cost or bandwidth reference