01-11-2008 11:53 AM - edited 03-05-2019 08:25 PM
I am having a area route distribution problem.
Router A
router ospf 1
log-adjacency-changes
auto-cost reference-bandwidth 1000000
area 10 nssa default-information-originate
area 20 nssa default-information-originate metric 5
area 30 nssa default-information-originate metric 5
timers throttle spf 1000 1000 1000
passive-interface default
no passive-interface Vlan100
no passive-interface Port-channel25
no passive-interface Port-channel27
no passive-interface Port-channel28
network 10.200.10.0 0.0.0.7 area 0
network 10.200.10.8 0.0.0.7 area 0
network 10.200.10.16 0.0.0.7 area 10
network 10.200.10.40 0.0.0.7 area 20
network 10.200.10.56 0.0.0.7 area 30
network 10.200.100.0 0.0.0.255 area 0
RouterB
router ospf 1
log-adjacency-changes
auto-cost reference-bandwidth 1000000
area 10 nssa default-information-originate
area 20 nssa default-information-originate
area 30 nssa default-information-originate
timers throttle spf 1000 1000 1000
passive-interface default
no passive-interface Vlan100
no passive-interface Port-channel24
no passive-interface Port-channel26
no passive-interface Port-channel27
network 10.200.10.0 0.0.0.7 area 0
network 10.200.10.8 0.0.0.7 area 0
network 10.200.10.24 0.0.0.7 area 20
network 10.200.10.32 0.0.0.7 area 20
network 10.200.10.48 0.0.0.7 area 30
network 10.200.100.0 0.0.0.255 area 0
Switch A has the following config.
router ospf 1
log-adjacency-changes
auto-cost reference-bandwidth 1000000
area 20 nssa
timers throttle spf 1000 1000 1000
redistribute connected subnets
passive-interface default
no passive-interface Port-channel26
no passive-interface Port-channel27
network 10.200.10.32 0.0.0.7 area 20
network 10.200.10.40 0.0.0.7 area 20
Switch B has the following config.
log-adjacency-changes
auto-cost reference-bandwidth 1000000
area 10 nssa
timers throttle spf 1000 1000 1000
redistribute connected subnets
passive-interface default
no passive-interface Port-channel28
network 10.200.10.16 0.0.0.7 area 10
When I do show route on Switch A, I only see routes for area 0 and not area 10.
When I do show route on Switch B, I only see routes for area 0 and not area 20.
On the routers A & B, I see all routes for everything.
How can I inject or distribute area 10 routes into area 20 from Routers A&B??
Right now everything is pingable because of the default routes are are redistributed from RouterA and RouterB.
Solved! Go to Solution.
01-11-2008 04:50 PM
You need to remove are 20 nssa from all routers containing that area, not just Switch B.
Also, make sure the command is actually gone. There are times when you have several options within the command, you need to issue the no area 20 nssa twice
01-11-2008 12:37 PM
You have to configure Area 10 and Area 20 as normal areas, not NSSA.
When you enabled NSSA in an OSPF area no type 3 or 4 summary LSAs are allowed. This means no inter-area routes (IA Routes).
Redistribution is allowed into a NSSA area but a type 5 (external route) is injected as type 7.
You can't redistribute between areas, you can only redistribute between two routing protocols.
I recommend reading the OSPF documentation:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124cg/hirp_c/ch15/1chospf.htm
HTH,
__
Edison.
01-11-2008 03:59 PM
So I removed the area 20 nssa and I cant create an adjacency for some reason.
01-11-2008 04:50 PM
You need to remove are 20 nssa from all routers containing that area, not just Switch B.
Also, make sure the command is actually gone. There are times when you have several options within the command, you need to issue the no area 20 nssa twice
01-13-2008 11:13 AM
Hi Edison,
You're right, removing nssa's will probably cut through the problem.
But: the recommended by you OSPF documentation states that nssa's will retain all the characteristics of stub areas, except that they will accept ASBR's and type-7 LSA's.
The document does not state that type-3 or type-4 LSA's are not allowed in nssa's. So interarea routes (O IA) should appear in the routing table.
I tried a living configuration and the interarea routes did appear for me in the routing table of nssa routers.
If any documentation states the contrary, it should not be true.
Why the expected routes do not appear in the routing table in the current nssa config? Well, I think there may be some causes that would stop propagation of routes across the area or electing them into the routing table.
We would need to see the complete running-configs to have ample information.
Best regards:
Istvan
01-13-2008 01:39 PM
Istvan,
You are correct, LSA Type 3 & 4 would be blocked with the no-summary option within the NSSA command.
Thanks for your contribution to this thread.
Regards,
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