[c-nsp] OSPF totally NSSA and route redistribution

Tue Sep 22 06:32:47 EDT 2015

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Hi,

I am trying ton convert a standard working  OSPF area into a totally NSSA
area but I do have problem with route metric.

I do not know if it is a design limit (or a bad design from myself..)

Thanks !

Here is the network diagram :

https://imagizer.imageshack.us/v2/517x363q90/r/909/2aWeLr.png

*OSPF STANDARD AREA*

Using GNS3 & C3725

*R1# (ABR)*

interface FastEthernet0/0

 ip address 10.40.24.1 255.255.255.0

 duplex auto

 speed auto

no shut

!

interface FastEthernet0/1

 ip address 10.25.2.2 255.255.255.0

 duplex auto

 speed auto

no shut

!

router ospf 252

 router-id 0.0.252.2

 log-adjacency-changes

 auto-cost reference-bandwidth 10000

 network 10.25.2.0 0.0.0.255 area 0

 network 10.40.24.0 0.0.0.255 area 324

*R8# (ABR)*

interface FastEthernet0/0

 ip address 10.30.24.1 255.255.255.0

 duplex auto

 speed auto

no shut

!

interface FastEthernet0/1

 ip address 10.25.2.1 255.255.255.0

 duplex auto

 speed auto

no shut

!

router ospf 252

 router-id 0.0.252.1

 log-adjacency-changes

 auto-cost reference-bandwidth 10000

 network 10.25.2.0 0.0.0.255 area 0

 network 10.30.24.0 0.0.0.255 area 324

*R2# (ASBR with redistribute static)*

interface FastEthernet0/0

 ip address 10.40.24.29 255.255.255.0

 ip ospf priority 0

 duplex auto

 speed auto

no shut

!

interface FastEthernet0/1

 ip address 10.30.24.29 255.255.255.0

 ip ospf priority 0

 duplex auto

 speed auto

no shut

!

interface FastEthernet1/0

 ip address 10.10.10.1 255.255.255.0

 duplex auto

 speed auto

no shut

!

router ospf 10

 router-id 0.3.24.29

 log-adjacency-changes

 auto-cost reference-bandwidth 10000

 redistribute static metric-type 1 subnets

 network 10.30.24.0 0.0.0.255 area 324

 network 10.40.24.0 0.0.0.255 area 324

!

ip route 71.71.71.0 255.255.255.0 10.10.10.2

*R3# (ASBR with redistribute static)*

interface FastEthernet0/0

 ip address 10.40.24.39 255.255.255.0

 ip ospf priority 0

 duplex auto

 speed auto

no shut

!

interface FastEthernet0/1

 ip address 10.30.24.39 255.255.255.0

 ip ospf priority 0

 duplex auto

 speed auto

no shut

!

interface FastEthernet1/0

 ip address 10.20.10.1 255.255.255.0

 duplex auto

 speed auto

no shut

!

router ospf 10

 router-id 0.3.24.39

 log-adjacency-changes

 auto-cost reference-bandwidth 10000

 redistribute static metric-type 1 subnets

 network 10.30.24.0 0.0.0.255 area 324

 network 10.40.24.0 0.0.0.255 area 324

!

ip route 72.72.72.0 255.255.255.0 10.20.10.2

*From R1 & R8, routes are OK*

R1#sh ip route ospf

     71.0.0.0/24 is subnetted, 1 subnets

O E1    71.71.71.0 [110/1020] via 10.40.24.29, 00:10:40, FastEthernet0/0

     10.0.0.0/24 is subnetted, 3 subnets

O       10.30.24.0 [110/2000] via 10.40.24.39, 00:10:50, FastEthernet0/0

                   [110/2000] via 10.40.24.29, 00:10:50, FastEthernet0/0

     72.0.0.0/24 is subnetted, 1 subnets

O E1    72.72.72.0 [110/1020] via 10.40.24.39, 00:10:40, FastEthernet0/0

R8#sh ip route ospf

     71.0.0.0/24 is subnetted, 1 subnets

O E1    71.71.71.0 [110/1020] via 10.30.24.29, 00:11:19, FastEthernet0/0

     10.0.0.0/24 is subnetted, 3 subnets

O       10.40.24.0 [110/2000] via 10.30.24.39, 00:11:19, FastEthernet0/0

                   [110/2000] via 10.30.24.29, 00:11:19, FastEthernet0/0

     72.0.0.0/24 is subnetted, 1 subnets

O E1    72.72.72.0 [110/1020] via 10.30.24.39, 00:11:19, FastEthernet0/0

*OSPF TOTALLY NSSA AREA*

Add following config :

*R1 & R8#*

router ospf 252

area 324 nssa no-summary

*R2 & R3#*

router ospf 10

area 324 nssa

*From R1 & R8, routes are duplicate / NOK / wrong metric*

R8#sh ip route ospf

     71.0.0.0/24 is subnetted, 1 subnets

*O E1    71.71.71.0 [110/2020] via 10.30.24.39, 00:00:31, FastEthernet0/0*

*                   [110/2020] via 10.30.24.29, 00:00:31, FastEthernet0/0*

     10.0.0.0/24 is subnetted, 3 subnets

O       10.40.24.0 [110/2000] via 10.30.24.39, 00:00:31, FastEthernet0/0

                   [110/2000] via 10.30.24.29, 00:00:31, FastEthernet0/0

     72.0.0.0/24 is subnetted, 1 subnets

*O E1    72.72.72.0 [110/2020] via 10.30.24.39, 00:00:31, FastEthernet0/0*

*                   [110/2020] via 10.30.24.29, 00:00:31, FastEthernet0/0*

R1#sh ip route ospf

     71.0.0.0/24 is subnetted, 1 subnets

O N1    71.71.71.0 [110/1020] via 10.40.24.29, 00:00:16, FastEthernet0/0

     10.0.0.0/24 is subnetted, 3 subnets

O       10.30.24.0 [110/2000] via 10.40.24.39, 00:00:16, FastEthernet0/0

                   [110/2000] via 10.40.24.29, 00:00:16, FastEthernet0/0

     72.0.0.0/24 is subnetted, 1 subnets

O N1    72.72.72.0 [110/1020] via 10.40.24.39, 00:00:16, FastEthernet0/0

2015-09-22 12:15 GMT+02:00 Nicolas V <nicovpp59 at gmail.com>:

> Hi,
>
> I am facing a metric / design problem with a totally NSSA setup.
>
> I have described my problem on cisco forums :
>
>
> https://supportforums.cisco.com/discussion/12612446/ospf-totally-nssa-and-route-redistribution
>
>
> Any clue would be helpful for us to begin to resolve this issue.
>
> Thanks,
> Nicolas
>