OSPF IP Prefix-List
R4 has Loopback 0 4.4.4.4 in area 0
other physical interfaces as shown in the topology they are in area 1,2,3
I have configured on R4:
R4#sh run | beg ip prefix
ip prefix-list INTO-AREA3 seq 5 deny 2.2.2.2/32
ip prefix-list INTO-AREA3 seq 10 permit 0.0.0.0/0 le 32
ip prefix-list INTO-AREA3 seq 15 deny 192.168.14.0/24
ip prefix-list INTO-AREA3 seq 20 deny 192.168.24.0/24
router ospf 1
area 3 filter-list prefix INTO-AREA3 in
when I go to R3 I see the routes below still there when they should be filtered out:
192.168.14.0/24
192.168.24.0/24
I have changed the sequence number of this command to sequence 25:
ip prefix-list INTO-AREA3 seq 25 permit 0.0.0.0/0 le 32
and now I see the filtering worked. When I go to R3 which is in area 3. I do not see the routes:
192.168.14.0/24
192.168.24.0/24
Any Expert to explain the logic that the route has used in regard to the ip prefix-list sequences. ?
Thank you
ASKER
if I understand after : permit 0.0.0.0/0 le 32
there is no other Prefix-list that will be looked at regardless of the sequence number ..Correct ?
there is no other Prefix-list that will be looked at regardless of the sequence number ..Correct ?
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ASKER
Thank you
You're welcome.
Statements
ip prefix-list INTO-AREA3 seq 15 deny 192.168.14.0/24
ip prefix-list INTO-AREA3 seq 20 deny 192.168.24.0/24
will never be checked since all routes will match sequence 10 permit 0.0.0.0/0 le 32