Multi-Area OSPF

I am studying OSPF and I have set up several routers in a MultiArea OSPF configuration.

2621XMA(area 0)----2621XMB(area 1)

The routing table in the 2621B reflects the routes from area 0 (they have the IA next to them) so I know that my ip addressing and configuration is correct. What I don't get is why I can ping any router from B execpt for A. Is this normal? BTW there are no entries in the routing tables of my other routers that reflect B. This is in PT.

Here are the configs from router A

     1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.5 is directly connected, Loopback1
     10.0.0.0/8 is variably subnetted, 6 subnets, 2 masks
O       10.1.1.0/24 [110/2] via 10.1.2.1, 00:56:59, FastEthernet0/0
C       10.1.2.0/24 is directly connected, FastEthernet0/0
C       10.1.3.0/24 is directly connected, Serial1/0
O       10.1.4.0/24 [110/782] via 10.1.3.2, 00:57:39, Serial1/0
O       10.1.5.0/24 [110/783] via 10.1.3.2, 00:55:29, Serial1/0
C       10.2.1.0/30 is directly connected, Serial1/1
version 12.2
service password-encryption
!
hostname "MultiArea Core Edge 1"
!
!
enable secret 5 $1$mERr$ef/QnOVeBLpbvfUfMm0wL.
!
!
!
!
username kevin password 7 08314D5D1A0E0A0516
!
ip ssh version 1
ip domain-name thebigone.com
!
!
interface Loopback1
 description loopback for MultiArea Core Edge 1
 ip address 1.1.1.5 255.255.255.255
!
interface FastEthernet0/0
 description connection the CORE ROUTER 3
 ip address 10.1.2.2 255.255.255.0
 duplex auto
 speed auto
!
interface FastEthernet0/1
 no ip address
 duplex auto
 speed auto
 shutdown
!
interface Serial1/0
 description connection the MultiArea Core Edge 2
 ip address 10.1.3.1 255.255.255.0
 clock rate 64000
!
interface Serial1/1
 description connection to Area 1
 ip address 10.2.1.1 255.255.255.252
 clock rate 64000
!
interface Serial1/2
 no ip address
!
interface Serial1/3
 no ip address
!
router ospf 1
 log-adjacency-changes
 network 10.1.2.0 0.0.0.255 area 0
 network 10.1.3.0 0.0.0.255 area 0
 network 10.2.1.0 0.0.0.3 area 1
!
ip classless
!
!
!
!
ip dhcp pool Kevin
!
no cdp run
!
banner motd ^C
This is my message of the day banner. The password for everything is me. ^C
line con 0
line vty 0 4
 login
!
!
end

Here are the configs from router B

AREA1LINKTOAREA0>en
Password: 
AREA1LINKTOAREA0#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
       i - IS-IS, 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

Gateway of last resort is not set

     10.0.0.0/8 is variably subnetted, 6 subnets, 2 masks
O IA    10.1.1.0/24 [110/783] via 10.2.1.1, 00:33:23, Serial1/0
O IA    10.1.2.0/24 [110/782] via 10.2.1.1, 00:33:23, Serial1/0
O IA    10.1.3.0/24 [110/1562] via 10.2.1.1, 00:33:23, Serial1/0
O IA    10.1.4.0/24 [110/1563] via 10.2.1.1, 00:33:23, Serial1/0
O IA    10.1.5.0/24 [110/1564] via 10.2.1.1, 00:33:23, Serial1/0
C       10.2.1.0/30 is directly connected, Serial1/0
AREA1LINKTOAREA0#
AREA1LINKTOAREA0#en
AREA1LINKTOAREA0#sho rin
                      ^
% Invalid input detected at '^' marker.
    
AREA1LINKTOAREA0#sh run
Building configuration...

Current configuration : 843 bytes
!
version 12.2
service password-encryption
!
hostname AREA1LINKTOAREA0
!
!
enable secret 5 $1$mERr$ef/QnOVeBLpbvfUfMm0wL.
!
!
!
!
username kevin password 7 08314D5D1A0E0A0516
!
ip ssh version 1
ip domain-name thebigone.com
!
!
interface FastEthernet0/0
 no ip address
 duplex auto
 speed auto
 shutdown
!
interface FastEthernet0/1
 no ip address
 duplex auto
 speed auto
 shutdown
!
interface Serial1/0
 description connection to area 0
 ip address 10.2.1.2 255.255.255.252
!
interface Serial1/1
 no ip address
!
interface Serial1/2
 no ip address
!
interface Serial1/3
 no ip address
!
router ospf 1
 log-adjacency-changes
 network 10.2.1.0 0.0.0.3 area 1
!
ip classless
!
!
!
!
ip dhcp pool Kevin
!
no cdp run
!
banner motd 
This is my message of the day banner. The password for everything is me. 
line con 0
line vty 0 4
 login
!
!
end

I included the routing table in the configs. I am not looking for a specific answer per se, if someone could point me in the right direction I would be happy

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Comments

ColbyG

I didn't look at your configs much, but you should start with basic troubleshooting. Do a traceroute, where does it die? What address is your ping sourcing from? Something like this is usually caused by the far destination not having a route back to the source. But you're also using PT, which is buggy as hell.

Bl8ckr0uter

ColbyNA wrote: »

I didn't look at your configs much, but you should start with basic troubleshooting. Do a traceroute, where does it die? What address is your ping sourcing from? Something like this is usually caused by the far destination not having a route back to the source. But you're also using PT, which is buggy as hell.

The thing is, I THINK I know what the issue is. I know that in order for a ping to work there must be a going map (route) and a getting back map (route). The issue is that on all but the router that is directly connected to Router B, they have no map at all of router b. Router B has routes for all of them but none of them have routes for router B. There is over 12 routers involved in this, (if this changes thing). 6 in Area 0, 6 in Area 1.

Pings and traceroutes confim my thinking. I just don't know how to fix it.

ColbyG

Advertise the routes to router B?

Bosefus

I had this problem in a BGP/EIGRP lab I did when I was working on my BSCI.

The ping was sourcing from an interface that the far end router did not have in its routing table.

To fix, I advertised the unknown interface.

Bl8ckr0uter

Bosefus wrote: »

I had this problem in a BGP/EIGRP lab I did when I was working on my BSCI.

The ping was sourcing from an interface that the far end router did not have in its routing table.

To fix, I advertised the unknown interface.

Um you did what?

Bl8ckr0uter

ColbyNA wrote: »

Advertise the routes to router B?

That's the thing, None of the Area0 routers have the route to Area 1 (along with Router

but All of the Area 1 Routers have routes to Area 0 (including router A).

ColbyG

knwminus wrote: »

Um you did what?

He told you to do what I said earlier. Make sure the other routers have a route back.

As for your latest post, I have no idea what you're saying.

Bl8ckr0uter

ColbyNA wrote: »

He told you to do what I said earlier. Make sure the other routers have a route back.

As for your latest post, I have no idea what you're saying.

I can put in a static route on all my routers but I am trying to do this dynamically.

Ok here is the routing table from Router A:

O IA    10.1.1.0/24 [110/783] via 10.2.1.1, 02:32:02, Serial1/0
O IA    10.1.2.0/24 [110/782] via 10.2.1.1, 02:32:02, Serial1/0
O IA    10.1.3.0/24 [110/1562] via 10.2.1.1, 02:32:02, Serial1/0
O IA    10.1.4.0/24 [110/1563] via 10.2.1.1, 02:32:02, Serial1/0
O IA    10.1.5.0/24 [110/1564] via 10.2.1.1, 02:32:02, Serial1/0
C       10.2.1.0/30 is directly connected, Serial1/0
C       10.2.2.0/24 is directly connected, FastEthernet0/0
O       10.2.3.0/24 [110/782] via 10.2.2.2, 01:34:45, FastEthernet0/0
O       10.2.4.0/24 [110/1563] via 10.2.2.2, 01:09:19, FastEthernet0/0
O       10.2.5.0/24 [110/1564] via 10.2.2.2, 00:59:30, FastEthernet0/0
O       10.2.6.0/24 [110/2345] via 10.2.2.2, 00:45:00, FastEthernet0/0

Those InterArea Routes are from Area 0. Router A is in Area 1.

Here is the routing table from Router B:

     1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.5 is directly connected, Loopback1
     10.0.0.0/8 is variably subnetted, 11 subnets, 2 masks
O       10.1.1.0/24 [110/2] via 10.1.2.1, 02:51:40, FastEthernet0/0
C       10.1.2.0/24 is directly connected, FastEthernet0/0
C       10.1.3.0/24 is directly connected, Serial1/0
O       10.1.4.0/24 [110/782] via 10.1.3.2, 02:52:20, Serial1/0
O       10.1.5.0/24 [110/783] via 10.1.3.2, 02:50:10, Serial1/0
C       10.2.1.0/30 is directly connected, Serial1/1
O       10.2.2.0/24 [110/782] via 10.2.1.2, 01:39:35, Serial1/1
O       10.2.3.0/24 [110/1563] via 10.2.1.2, 01:36:09, Serial1/1
O       10.2.4.0/24 [110/2344] via 10.2.1.2, 01:10:43, Serial1/1
O       10.2.5.0/24 [110/2345] via 10.2.1.2, 01:00:55, Serial1/1
O       10.2.6.0/24 [110/3126] via 10.2.1.2, 00:46:24, Serial1/1

All of the routes that start with 10.2 are from Area 1. The rest are from Area 0. 2 things to notice here: The First is that the routes that are from area 1 do not say IA like they should (see previous output). The second is that obvious a ping would (and does) work from this router only. Which is why I am so confused.

This is the routing table from another router in Area 0, lets call it router B-2:

      1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback1
     10.0.0.0/24 is subnetted, 5 subnets
C       10.1.1.0 is directly connected, FastEthernet0/0
O       10.1.2.0 [110/2] via 10.1.1.3, 02:55:39, FastEthernet0/0
O       10.1.3.0 [110/783] via 10.1.1.3, 02:55:39, FastEthernet0/0
O       10.1.4.0 [110/784] via 10.1.1.3, 02:55:39, FastEthernet0/0
O       10.1.5.0 [110/785] via 10.1.1.3, 02:54:09, FastEthernet0/0

Now obviously a ping from a device in Area 1 (the 10.2 ip address) won't work because this router does not know how to get to those routers.

However look at the routing table from another router in Area 1, lets call it A-2

     1.0.0.0/32 is subnetted, 1 subnets
C       1.1.2.6 is directly connected, Loopback1
     10.0.0.0/8 is variably subnetted, 12 subnets, 2 masks
O IA    10.1.1.0/24 [110/3128] via 10.2.6.1, 00:40:39, Serial1/0
O IA    10.1.2.0/24 [110/3127] via 10.2.6.1, 00:53:30, Serial1/0
O IA    10.1.3.0/24 [110/3907] via 10.2.6.1, 00:53:30, Serial1/0
O IA    10.1.4.0/24 [110/3908] via 10.2.6.1, 00:53:30, Serial1/0
O IA    10.1.5.0/24 [110/3909] via 10.2.6.1, 00:53:30, Serial1/0
O       10.2.1.0/30 [110/3126] via 10.2.6.1, 00:53:30, Serial1/0
O       10.2.2.0/24 [110/2345] via 10.2.6.1, 00:53:30, Serial1/0
O       10.2.3.0/24 [110/2344] via 10.2.6.1, 00:53:30, Serial1/0
O       10.2.4.0/24 [110/1563] via 10.2.6.1, 00:53:30, Serial1/0
O       10.2.5.0/24 [110/782] via 10.2.6.1, 00:53:30, Serial1/0
C       10.2.6.0/24 is directly connected, Serial1/0
C       10.4.1.0/30 is directly connected, Serial1/1

As you can see, the InterArea Routes show up, as they should.
The thing I don't understand is why don't the routers in Area 0 have a converse but similar routing table? Why don't they show IA routes pointing to the 10.2 ip address (those in Area 1)? I thought maybe it was an issue with PT but I am not sure now, possibly my config is wrong.

Does this make sense (my explanation and the issue) ?

networker050184

I'm having a hard time following your issue since you haven't told us what address you are pinging from or to. You should throw this on dynamips or regualr equipment and see how it reacts. I try to never troubleshoot anything on PT. From what I know its designed for CCNA level stuff and this is beyond that scope.

Also, I think you are getting in a little over your head here. Work on understanding basic routing and reach ability before you try to jump into more complex situations.

Bl8ckr0uter

networker050184 wrote: »

I'm having a hard time following your issue since you haven't told us what address you are pinging from or to. You should throw this on dynamips or regualr equipment and see how it reacts. I try to never troubleshoot anything on PT. From what I know its designed for CCNA level stuff and this is beyond that scope.

In my OP I said I was pinging 10.2.1.1 from 10.2.1.2 (which works) but I cannot ping anything in Area 0 from Area 1 (the 10.2) due to the lack of routes in the Area 0 routing tables that point to Area 1. There are no IA routes. For some reason, they are not showing up. That is the issue. I have looked over debug outputs for ospf and everything is forming adj. just fine but for some reason the IA routes are not being injected into the routing tables.

networker050184 wrote: »

Also, I think you are getting in a little over your head here. Work on understanding basic routing and reach ability before you try to jump into more complex situations.

There is only so many times I can set up rip on a network. I can set up these routing protocols quite literally in my sleep. This isn't as difficult as it looks. I'm bored and I wanted to try something different. My configs look right. I am even willing to believe that they are right. But no one can confirm or deny this.

In a situation where there are 2 Areas, there should be IA routes injected in the routing tables of routers in both Areas that point to the other Area. I dont have access to enough routers to test this out and I don't have a machine powerful enough to run gns3 right now. I am building a computer but until then PT is what I have. If you are thinking that this is an issue with PT (which I have had several) then that is what thing, but telling me to focus on something else is educationally hindering. I need to know this and I needed to know this yesterday and this is the only medium that I can test this now (which I know is a bad thing).

pureblue

You need to check your link state database, check type 3 network summary lsa's...

AlexMR

As networker said, try to run your configuration in GNS3. These things can get quite complex by themselves, if you add the issue of testing the limits of packet tracer you are putting yourself in a very tough postition, where you might end up frustrated and clueless.

That said, i would suggest you add the network types for the OSPF process running in the interfaces, with the interface configuration command -ip ospf network [broadcast, point-to-point, point-to-multipoint, etc].

I am going to give it a try again, because I didnt understand the problem when i first read it.

AlexMR

"im studying OSPF and I have set up several routers in a MultiArea OSPF configuration.

2621XMA(area 0)----2621XMB(area 1)

The routing table in the 2621B reflects the routes from area 0 (they have the IA next to them) so I know that my ip addressing and configuration is correct. What I don't get is why I can ping any router from B execpt for A. Is this normal? "

You mean router A is your ABR and you can ping routes advertised by it but cant ping router A's own interfaces? Nevermind, reread your last post...try doing what i told you in the previous post and let me know.

PT was meant to let you configure simple OSPF routing, I dont think inter-area routing was in the CCNA, but i could be wrong.

Bl8ckr0uter

I am not sure what happen but everything is working now.

Here is what I think the issue was: In PT you have the ability to visualize the network traffic. I happened to notice that the buffer was filling up rather quickly due to the amount of routers I have (18+). Today I opened PT without launching the simulated traffic visualizer and all of the IA routes showed up without an issue.

a random router in Area 0

     1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback1
     10.0.0.0/8 is variably subnetted, 11 subnets, 2 masks
C       10.1.1.0/24 is directly connected, FastEthernet0/0
O       10.1.2.0/24 [110/2] via 10.1.1.3, 00:28:39, FastEthernet0/0
O       10.1.3.0/24 [110/783] via 10.1.1.3, 00:28:29, FastEthernet0/0
O       10.1.4.0/24 [110/784] via 10.1.1.3, 00:28:29, FastEthernet0/0
O       10.1.5.0/24 [110/785] via 10.1.1.3, 00:28:29, FastEthernet0/0
O IA    10.2.1.0/30 [110/783] via 10.1.1.3, 00:28:29, FastEthernet0/0
O IA    10.2.2.0/24 [110/784] via 10.1.1.3, 00:28:29, FastEthernet0/0
O IA    10.2.3.0/24 [110/1565] via 10.1.1.3, 00:28:29, FastEthernet0/0
O IA    10.2.4.0/24 [110/2346] via 10.1.1.3, 00:28:29, FastEthernet0/0
O IA    10.2.5.0/24 [110/2347] via 10.1.1.3, 00:28:29, FastEthernet0/0
O IA    10.2.6.0/24 [110/3128] via 10.1.1.3, 00:28:29, FastEthernet0/0

Random router in Area 1

1.0.0.0/32 is subnetted, 1 subnets
C       1.1.2.2 is directly connected, Loopback1
     10.0.0.0/8 is variably subnetted, 11 subnets, 2 masks
O IA    10.1.1.0/24 [110/784] via 10.2.2.1, 00:29:17, FastEthernet0/0
O IA    10.1.2.0/24 [110/783] via 10.2.2.1, 00:29:17, FastEthernet0/0
O IA    10.1.3.0/24 [110/1563] via 10.2.2.1, 00:29:17, FastEthernet0/0
O IA    10.1.4.0/24 [110/1564] via 10.2.2.1, 00:29:17, FastEthernet0/0
O IA    10.1.5.0/24 [110/1565] via 10.2.2.1, 00:29:17, FastEthernet0/0
O       10.2.1.0/30 [110/782] via 10.2.2.1, 00:29:27, FastEthernet0/0
C       10.2.2.0/24 is directly connected, FastEthernet0/0
C       10.2.3.0/24 is directly connected, Serial1/0
O       10.2.4.0/24 [110/1562] via 10.2.3.2, 00:30:07, Serial1/0
O       10.2.5.0/24 [110/1563] via 10.2.3.2, 00:30:07, Serial1/0
O       10.2.6.0/24 [110/2344] via 10.2.3.2, 00:29:27, Serial1/0

Now that I know what the issue is, I will now populate my third area and move on to redistribution into Eigrp for a 4th set of routers to round off my layer 3 routing stuff.
Sorry about all the bitching, I just really want my CCNA and I am working with a bunch of CCNPs on my team and guys with tons of exp and it bothers me that they have something I want

. Plus Im the youngest guy here and everyone seems so far away. I feel like Saskue looking at the back of itachi; they are so far away (Naruto Fans will know what I am talking about, remember season one?). So I feel like the only way I can match them (until I get my CCNA/CCNA:S/CCNP/CCSP/CCIP) is to be on par with them in terms of knowledge and ability and if i can get some stupid ass multiarea OSPF to work in PT then I will feel like a failure. So If I was pressing that is the reason, because I want to be better than the best.

Redistro here I come, then VTP/STP/Switchport security. CCNA I can taste it!!!

Bl8ckr0uter

AlexMR wrote: »

"im studying OSPF and I have set up several routers in a MultiArea OSPF configuration.

2621XMA(area 0)----2621XMB(area 1)

The routing table in the 2621B reflects the routes from area 0 (they have the IA next to them) so I know that my ip addressing and configuration is correct. What I don't get is why I can ping any router from B execpt for A. Is this normal? "

You mean router A is your ABR and you can ping routes advertised by it but cant ping router A's own interfaces? Nevermind, reread your last post...try doing what i told you in the previous post and let me know.

PT was meant to let you configure simple OSPF routing, I dont think inter-area routing was in the CCNA, but i could be wrong.

It got fixed. PT was being stupid and stopping before the routers could be injected.