OSPF LAB and odd ABR behavior

[steeilers]

All,

Thanks in advance,

I am implementing multi area OSPF in packet tracer and I'm getting weird problems. Please see attached topology image. My area 5 AVVChandler MX84 router which is the area 5 router works just fine, it gets all routes for all networks.

- 

AVVCH-MX84#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, 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 10.12.0.0/24 [110/3] via 10.12.8.2, 00:06:05, GigabitEthernet0/2

C 10.12.8.0/24 is directly connected, GigabitEthernet0/2

L 10.12.8.1/32 is directly connected, GigabitEthernet0/2

O IA 10.24.0.0/24 [110/3] via 10.12.8.2, 00:06:05, GigabitEthernet0/2

O IA 10.160.213.0/24 [110/3] via 10.12.8.2, 00:06:05, GigabitEthernet0/2

O IA 10.252.0.0/24 [110/2] via 10.12.8.2, 00:06:25, GigabitEthernet0/2

O IA 192.168.128.0/24 [110/3] via 10.12.8.2, 00:06:05, GigabitEthernet0/2

My area 4 MX84 for North Phoenix is working fine generating all routes

When I look at the 

:show ip ospf database I can see they is getting all the routes from the ABR.

After double, tripple, and quadruple checking the ABR settings on all my ABR and all my inter-area routers all the config is the same

Now for areas 1, 2, 3 They populate one route from their ABR, which is the area 0 backbone network

AVVSurprise example from mx84

AVVSur-MX84#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, 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, 3 subnets, 2 masks

C 10.12.0.0/24 is directly connected, GigabitEthernet0/2

L 10.12.0.5/32 is directly connected, GigabitEthernet0/2

O IA 10.252.0.0/24 [110/2] via 10.12.0.6, 00:07:55, GigabitEthernet0/2

You can see the neighbor for AVV Surprise MX84 

AVVSur-MX84#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

5.5.5.5 1 FULL/BDR 00:00:31 10.12.0.6 GigabitEthernet0/2

you can see here it database isn't getting all the routes from it's ABR

AVVSur-MX84#show ip ospf database

OSPF Router with ID (6.6.6.6) (Process ID 1)

Router Link States (Area 3)

Link ID ADV Router Age Seq# Checksum Link count

6.6.6.6 6.6.6.6 699 0x80000002 0x003eaf 1

5.5.5.5 5.5.5.5 699 0x80000002 0x009b58 1

Net Link States (Area 3)

Link ID ADV Router Age Seq# Checksum

10.12.0.5 6.6.6.6 699 0x80000001 0x000119

Summary Net Link States (Area 3)

Link ID ADV Router Age Seq# Checksum

10.252.0.0 5.5.5.5 740 0x80000001 0x009ea4

If you check his ABR AVV Surprise eLAN you see he has all the routes, but he isn't sharing

AVVSurprise-eLAN#show ip ospf database

OSPF Router with ID (5.5.5.5) (Process ID 1)

Router Link States (Area 0)

Link ID ADV Router Age Seq# Checksum Link count

5.5.5.5 5.5.5.5 784 0x80000003 0x007758 1

9.9.9.9 9.9.9.9 784 0x80000003 0x00545a 1

7.7.7.7 7.7.7.7 778 0x80000003 0x00bce0 1

3.3.3.3 3.3.3.3 774 0x80000004 0x00501c 1

1.1.1.1 1.1.1.1 774 0x80000002 0x0081cd 1

Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum

10.252.0.166 9.9.9.9 774 0x80000004 0x0072f2

Summary Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum

10.12.0.0 5.5.5.5 814 0x80000001 0x00e94a

10.12.8.0 9.9.9.9 819 0x80000001 0x001903

192.168.128.0 7.7.7.7 819 0x80000001 0x0089ce

10.160.213.0 1.1.1.1 819 0x80000001 0x003b9e

10.24.0.0 3.3.3.3 820 0x80000001 0x00959a

Router Link States (Area 3)

Link ID ADV Router Age Seq# Checksum Link count

5.5.5.5 5.5.5.5 779 0x80000002 0x009b58 1

6.6.6.6 6.6.6.6 779 0x80000002 0x003eaf 1

Net Link States (Area 3)

Link ID ADV Router Age Seq# Checksum

10.12.0.5 6.6.6.6 779 0x80000001 0x000119

Summary Net Link States (Area 3)

Link ID ADV Router Age Seq# Checksum

10.252.0.0 5.5.5.5 820 0x80000001 0x009ea4

AVV Surprise eLAN neighbors

Neighbor ID Pri State Dead Time Address Interface

9.9.9.9 1 FULL/DR 00:00:37 10.252.0.166 GigabitEthernet0/0

1.1.1.1 1 2WAY/DROTHER 00:00:37 10.252.0.71 GigabitEthernet0/0

7.7.7.7 1 FULL/BDR 00:00:37 10.252.0.199 GigabitEthernet0/0

3.3.3.3 1 2WAY/DROTHER 00:00:37 10.252.0.24 GigabitEthernet0/0

6.6.6.6 1 FULL/DR 00:00:37 10.12.0.5 GigabitEthernet0/1

AVVSurprise-eLAN#

AVV Surprise elan config for verification 

interface GigabitEthernet0/0

ip address 10.252.0.165 255.255.255.0

duplex auto

speed auto

!

interface GigabitEthernet0/1

ip address 10.12.0.6 255.255.255.0

duplex auto

speed auto

router ospf 1

router-id 5.5.5.5

log-adjacency-changes

network 10.252.0.0 0.0.0.255 area 0

network 10.12.0.0 0.0.0.255 area 3

AVV Surprise MX84 info for verification 

interface GigabitEthernet0/2

ip address 10.12.0.5 255.255.255.0

duplex auto

speed auto

router ospf 1

router-id 6.6.6.6

log-adjacency-changes

network 10.12.0.0 0.0.0.255 area 3

Like i said I have double, tripple, and quadruplely checked my config, and it matches with the areas that are working. Kinda going crazy, I feel like packet tracer is acting buggy, please ignore the ASAs they are phase 2 for setting up failover VPN tunnels that are statically set with higher admin distance than ospf for alternate route if elan goes down. Anyone have any thoughts? Sorry for information overload.

I haven't confirmed 100% but when i reload the save i feel the working areas change, and the ones not working correctly change, will need to reload to see if something is weird with packet tracer, thanks again,

Steven

[Meheretab Mengistu]

Hi Steven,

AVVSur-MX84 is learning only one route with metric value of 2. It is not learning the other routes with value of 3. Please share the output of the following command:
AVVSurprise-eLAN#show ip ospf database summary
and also,
AVVSurprise-eLAN#show run | sec ospf

It could help us to see if it is, in case, not a bug.

Thanks!

[steeilers]

AVVSurprise-eLAN#show ip ospf database summary

OSPF Router with ID (5.5.5.5) (Process ID 1)

Summary Net Link States (Area 0)

LS age: 165

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 10.12.0.0 (summary Network Number)

Advertising Router: 5.5.5.5

LS Seq Number: 80000003

Checksum: 0xe54c

Length: 28

Network Mask: /24

TOS: 0 Metric: 1

LS age: 170

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 192.168.128.0 (summary Network Number)

Advertising Router: 7.7.7.7

LS Seq Number: 80000003

Checksum: 0x85d0

Length: 28

Network Mask: /24

TOS: 0 Metric: 1

LS age: 170

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 10.12.8.0 (summary Network Number)

Advertising Router: 9.9.9.9

LS Seq Number: 80000003

Checksum: 0x1505

Length: 28

Network Mask: /24

TOS: 0 Metric: 1

LS age: 169

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 10.160.213.0 (summary Network Number)

Advertising Router: 1.1.1.1

LS Seq Number: 80000003

Checksum: 0x37a0

Length: 28

Network Mask: /24

TOS: 0 Metric: 1

LS age: 169

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 10.24.0.0 (summary Network Number)

Advertising Router: 3.3.3.3

LS Seq Number: 80000003

Checksum: 0x919c

Length: 28

Network Mask: /24

TOS: 0 Metric: 1

Summary Net Link States (Area 3)

LS age: 171

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 10.252.0.0 (summary Network Number)

Advertising Router: 5.5.5.5

LS Seq Number: 80000003

Checksum: 0x9aa6

Length: 28

Network Mask: /24

TOS: 0 Metric: 1

AVVSurprise-eLAN#

 you can't run pipe commands in packet tracer  but this is the show run for ospf

router ospf 1

router-id 5.5.5.5

log-adjacency-changes

network 10.252.0.0 0.0.0.255 area 0

network 10.12.0.0 0.0.0.255 area 3

[Georg Pauwen]

Hello,

post the Packet Tracer file, so we can have a look at your configuration...

[steeilers]

i tried to attach the lab, it doesn't like the extension nor zipped.

[Georg Pauwen]

Change the file extension to .jpg.

The forum was recently altered and doesn't let you upload .pkt files anymore...

[Meheretab Mengistu]

Could you share the output of "show ip route" on AVVSurprise-eLAN ?

I do not see the "Routing Bit is set on this LSA" on all of the LSA 3 routes.

[steeilers]

see attachment, change extension back to .pkt to view my lab, thanks again

[Georg Pauwen]

Hello,

the file is empty. Did you save it is a .pkt and then renamed it to .jpg ?

[steeilers]

yes, i converted my saved file to a .jpg and uploaded it. I show the .jpg file and the .pkt save on my local computer side by side, they are both 121kb, so uploading it to the site must have messed it up somehow. sorry cisco forums may not be allowing it, i'll attach it again as a jpg here.

[steeilers]

I just downloaded it from my forum post and converted it back to .pkt and it worked just fine.

[Georg Pauwen]

I got the file. I'll have a look...

[steeilers]

tysir

[Georg Pauwen · Accepted solution]

Hello,

in your configuration, the routers have different DRs and BDRs. I have set the 'ip ospf priority' on interface GigabitEthernet0/0 on the area 1 ABR to 2, and on the area 2 ABR to 1, the rest of the GigabitEthernet0/0 interfaces has the priority set to 0, so they won't participate in the election. Once that is done, all area 0 routers have the same DR and BDR. And the link state database is consistent across all routers.

[steeilers]

strange, I tried manipulating that by making the router-id on my backbone router higher than all the others and then disconnecting, my studies for CCNA didn't talk alot about priority, but I did wonder about that, thanks for your help. at least all this troubleshooting got me very familar with OSPF for my icnd2 test mid next month, thanks again,