injecting a default-route by an ASBR into OSPF domain and reaching the ABR

[Mehdi.a.majid1]

What I want to do here is to generate a default-route on BR4 ( Totally NSSA ) which till this part it is simple

by

BR4(config-router)#area 4 nssa default-information-originate metric-type 1

and advertisement of this default-route reaches the HQ ( ABR & ASBR ) but the HQ does not consider it,

how can I make the HQ to consider it , what are the ways to do that ?

I appreciate any help that I can get.

[paul driver]

Hello

HQ
route ospf 1
area 4 nssa no-summary
no ip route 9.9.9.9 255.255.255.255 44.44.44.2
ip route 9.9.9.9 255.255.255.255 gig0/3 44.44.44.2

BR4
router ospf 1
no redistribute static
no ip route 8.8.8.8 255.255.255.255 44.44.44.1

ip route 8.8.8.8 255.255.255.255 gig0/1 44.44.44.1

clear ip ospf process

BR4-HQ
sh ip route
sh ip ospf database nssa-external

[Mehdi.a.majid1]

Hello,

I edited the confing but by the current config of BR4 I should see N2 default-route in HQ which I don't see

that anyway I changed the config as I attached to have N1.

and for the BGP redistribution:

BR4(config-router)#do show ip bgp
BGP table version is 3, local router ID is 44.0.0.4
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 *>  0.0.0.0          209.65.200.225                         0 65001 i
 *>  8.8.4.4/32       209.65.200.225           0             0 65001 i
BR4(config-router)#

HQ#show ip route

...

O N2     8.8.4.4 [110/1] via 10.4.4.4, 00:01:52, Tunnel4

...

Thanks.

[paul driver]

Hello

You are not showing all the route table ( i expected to see also connected and eigrp routes) - can you do so also amend the static routing to what i posted by defining the physical next hop of either gre tuinnel destination -  Can you clear the ospf process also please.

Also on those config you attached the tunnel4 of BR4 isn't in an ospf area ?

HQ-BR4
sh ip route
sh ip ospf da nssa-external
sh ip ospf interface brief

[Mehdi.a.majid1]

paul driver

Hello,

here I attached the asked info

Thanks.

[paul driver]

Hello

I see a N1 route from HQ into BR4 which shouldn't be their, Your HQ opsf process config is incorrect.

Please doing the following and test again

HQ
no router ospf 1

router ospf 1
router-id 1.0.4.0
area 4 nssa
 redistribute eigrp 100 metric-type 1 subnets tag 100
 network 172.16.1.0 0.0.0.7 area 0
 network 172.16.2.0 0.0.0.7 area 0
 network 192.168.123.0 0.0.0.15 area 1

[Mehdi.a.majid1]

Hi,

I need the HQ to know the area 4 as Totally NSSA area

HQ :

router ospf 1
router-id 1.0.4.0
 area 4 nssa no-summary

Because I can achieve what I want when area 4 is just NSSA but the problem appears when area 4 is Totally NSSA

Thanks

[paul driver]

HelloI

---

@Mehdi.a.majid1 wrote:

Hi,

I need the HQ to know the area 4 as Totally NSSA area

HQ :

router ospf 1
router-id 1.0.4.0
 area 4 nssa no-summary

Because I can achieve what I want when area 4 is just NSSA but the problem appears when area 4 is Totally NSSA

Thanks

---

It is already from no summary at BR4 anyway ,dont forget it isnt the router thats the total stub its the area and your injecting a default from the ASBR not the ABR also.

TBH i shouldn't make a difference having the no-summary at both ends but its good practice not to do it.

[Mehdi.a.majid1]

paul driver

Hi,

It is already from no summary at BR4 anyway ,dont forget it isnt the router thats the total stub its the area and your injecting a default from the ASBR not the ABR also.

TBH i shouldn't make a difference having the no-summary at both ends but its good practice not to do it.

At BR4 it doesn't matter if I issue #area 4 nssa or #area 4 nssa no summary , but sure it has a huge difference at HQ to the ospf domain and when at HQ I issue # #area 4 nssa  then it makes the area 4 nssa (which allows the Type-3 LSAs into area 4) but when at HQ I issue #area 4 nssa no summary  then it  makes the area 4 Totally NSSA which does not allow Type-3 LSA and Type-5 LSAs.

So here I need to know that is it possible by such a OSPF design that having the area 4 as a Totally NSSA and also receiving the redistributed BGP default-Route or BR4's generated default-route and have it in the HQ's routing table ?! if it is possible why and if it is not then what is the reason ?

Thanks.

[Georg Pauwen]

Hello,

I haven't followed the entire thread, but possibly your NAT is the problem ?

Try and change access list 4 to:

access-list 4 permit 192.168.40.1 0.0.0.127
access-list 4 permit 44.44.44.0 0.0.0.7

--> add any other networks you need to have translated

as 'permit any' is not a good idea usually...

[paul driver]

Hello

---

@Georg Pauwen wrote:

Hello,

I haven't followed the entire thread, but possibly your NAT is the problem ?

It this case it shouldn't have any bearing on ospf default route injection

[Mehdi.a.majid1]

Georg Pauwen

Hi,

I did what you said but no effect on the goal.

Thanks.

[Georg Pauwen]

Hello,

odd. I loaded your lab, and there is no way I can even get the N2 default route OUT of the routing table of HQ...

Not sure what has been posted, but what is the output of 'show ip route' of BR4 ?

[paul driver]

Hello

---

@Georg Pauwen wrote:

Hello,

odd. I loaded your lab, and there is no way I can even get the N2 default route OUT of the routing table of HQ...

---

You shouldn't and dont need to as the default route needs to comes from the BR4 not HQ.

The OP wanted the area 4 to be Not-So-Tottally Stubby Area and it is that with BR4, As i have stated there is not need for the no-summary to be applied on the HQ side however it seems OP isnt adhering to this.

[Georg Pauwen]

I am lost to be honest. The original problem was that the N2 default route wasn't getting into the routing table of HQ. It was coming from BR4, but for some reason wouldn't show up in the routing table of HQ with 'show ip route' ?

Maybe OP can clarify...

[Mehdi.a.majid1]

Hello,

BR4(config-router)#do show ip route
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is 209.65.200.225 to network 0.0.0.0

B*    0.0.0.0/0 [20/0] via 209.65.200.225, 00:27:47
      5.0.0.0/32 is subnetted, 1 subnets
C        5.0.0.5 is directly connected, Loopback5
      8.0.0.0/32 is subnetted, 2 subnets
B        8.8.4.4 [20/0] via 209.65.200.225, 00:27:47
S        8.8.8.8 [1/0] via 44.44.44.1
      9.0.0.0/32 is subnetted, 1 subnets
C        9.9.9.9 is directly connected, Loopback4
      10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        10.4.4.0/24 is directly connected, Tunnel4
L        10.4.4.4/32 is directly connected, Tunnel4
      44.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        44.44.44.0/29 is directly connected, GigabitEthernet0/1
L        44.44.44.2/32 is directly connected, GigabitEthernet0/1
      192.168.40.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.40.0/25 is directly connected, GigabitEthernet0/2
L        192.168.40.1/32 is directly connected, GigabitEthernet0/2
      209.65.200.0/24 is variably subnetted, 2 subnets, 2 masks
C        209.65.200.224/30 is directly connected, GigabitEthernet0/0
L        209.65.200.226/32 is directly connected, GigabitEthernet0/0
BR4(config-router)#