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OSPF router getting wrong routes

KenThomassen
Level 1
Level 1

Hey everybody,

I'm working on a project with IPv6 and am currently trying out some stuff with OSPF.

But when i configure a network zith 3 routers, 1 routers always gets wrong routes (Router3).

What might be causing this or how can i fix/prevent this?

I have ipv6 enabled on all the interfaced and the routers have ipv6 unicast-routing.

test2-ospf.PNG

Router3 ospf route:

O   FC00::/64 [110/2]

     via FE80::209:7CFF:FE9B:E802, FastEthernet1/1

O   FC00:0:0:1::/64 [110/2]

     via FE80::20C:85FF:FE48:DA01, FastEthernet1/1

O   FC00:0:0:4::/64 [110/2]

     via FE80::20C:85FF:FE48:DA01, FastEthernet1/1

 

So whenever a packet has to go over Router3 - FA1/0 it fails because there is no route

and there is no dubbel route for when it has to go to network FC00:0:0:1::/64

Router1 ospf route:

O   FC00:0:0:2::/64 [110/2]

     via FE80::20C:85FF:FE48:DA02, FastEthernet1/0

     via FE80::202:16FF:FE30:8301, FastEthernet1/1

O   FC00:0:0:4::/64 [110/2]

     via FE80::20C:85FF:FE48:DA02, FastEthernet1/0

O   FC00:0:0:5::/64 [110/2]

     via FE80::202:16FF:FE30:8301, FastEthernet1/1

Router2 ospf route:

O   FC00::/64 [110/2]
     via FE80::209:7CFF:FE9B:E801, FastEthernet1/1
O   FC00:0:0:3::/64 [110/2]
     via FE80::209:7CFF:FE9B:E801, FastEthernet1/1
     via FE80::202:16FF:FE30:8302, FastEthernet1/0
O   FC00:0:0:5::/64 [110/2]
     via FE80::202:16FF:FE30:8302, FastEthernet1/0

Thanks in advance!

Best regards,

Thomassen Ken

6 Replies 6

Abzal
Level 7
Level 7

Hi,

You may need to check OSPF configuration of interfaces between R1/R3. Because R3 is not establishing neighbor relationship with R1 as result does not see routes that R1 is advertising.

R1:

sh ipv6 protocols

sh ipv6 ospf ne

sh ipv6 ospf int

Hope it will help.

Best regards,
Abzal

Best regards,
Abzal

Hey Abzal,

Thank you for the fast responce.

I have looked into the items you stated in your post.

Everything looks fine to me, but the problem is still there.

i have included a text file with the output of the

show ipv6 protocols

show ipv6 ospf neighbor

show ipv6 ospf interface

maybe i overlooked something?

Best regards,

Ken Thomassen

Hi Ken,

I've looked output you provided and config look OK. But I need some extra info:

R3:

sh run | sec router ospf

The problem might be configured maximum-paths command under OSPFv3 configuration. As you might know OSPF does only equal load balancing. Everything else looks correct for me.

http://www.cisco.com/en/US/tech/tk827/tk831/technologies_tech_note09186a0080094806.shtml

Note. I've checked on GNS3 lab worked prefectly. I didn't tried it on Packet Tracer.

Hope it will help.

Best regards,
Abzal

Best regards,
Abzal

Hi Ken,

The only thing that I find abnormal is the following:

Router3 ospf route:

O   FC00::/64 [110/2]

     via FE80::209:7CFF:FE9B:E802, FastEthernet1/1

The link-local adddress is from R1 and the interface is to R2. This points to either a bug or misconfiguration. What IOS version are you running on R3? Could you please provide the full configuration for R1, R2 and R3?

Regards

Regards,
Harold Ritter, CCIE #4168 (EI, SP)

KenThomassen
Level 1
Level 1

Hi,

I am using Packet Tracer 5.3.3

@Abzal: I have tried the maximum paths for ospf, but the packet tracer routers do not recognise these commands. Packet Tracer also does not recognise the pipe command "sh run | sec router ospf"

@Harold: I have included the running-config off the routers with the version they are running (the same on all).

Best regards,

Ken

Ken,

The configs look good. The only issue I can see at this point is a problem with the IOS version running in this lab. 12.4(15)T1 is quite old. It would definitely be worth upgrading to a more recent version.

Regards

Regards,
Harold Ritter, CCIE #4168 (EI, SP)