Cisco Cisco IOS Software Release 12.0(15)S White Paper
ABR Type 3 LSA Filtering
Monitoring and Maintaining ABR Type 3 LSA Filtering
4
Cisco IOS Release 12.0(15)S
===> Area-filter AREA_0_IN in
===> Area-filter AREA_0_OUT out
Number of LSA 5. Checksum Sum 0x29450
Number of opaque link LSA 0. Checksum Sum 0x0
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
Area 1
Number of interfaces in this area is 1
Area has no authentication
SPF algorithm executed 4 times
Area ranges are
===> Area-filter AREA_1_IN in
===> Area-filter AREA_1_OUT out
Number of LSA 6. Checksum Sum 0x30100
Number of opaque link LSA 0. Checksum Sum 0x0
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
Monitoring and Maintaining ABR Type 3 LSA Filtering
Configuration Examples
The following configuration example output shows interarea filtering that is applied to both incoming
and outgoing routes:
and outgoing routes:
Router(config)# router ospf 1
log-adjacency-changes
area 1 filter-list prefix AREA_1_OUT out
area 3 filter-list prefix AREA_3_IN in
network 11.0.0.0 0.255.255.255 area 3
network 20.1.1.0 0.0.0.255 area 0
network 55.0.0.0 0.255.255.255 area 1
!
ip prefix-list AREA_1_OUT seq 10 permit 35.25.0.0/8 ge 16
ip prefix-list AREA_1_OUT seq 20 permit 192.20.20.0/24
!
ip prefix-list AREA_3_IN seq 10 permit 172.17.0.0/16
!
!
Command
Purpose
Router# show ip prefix-list
Displays information about a prefix list or prefix
list entries.
list entries.