cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
943
Views
5
Helpful
1
Replies

Need help with ospf lab

Hello,

I was wondering if you could help me :

I was doing the lab 3-2 on this pdf : http://www.kis.fri.uniza.sk/~palo/Netacad/LST/ccnp-route-v6/en_ROUTE_SLM_v6000.pdf

I used this configuration the the three routers :

Router R1
hostname R1
!
interface Loopback1
description Engineering Department
ip address 10.1.1.1 255.255.255.0
ip ospf network point-to-point
!
interface Serial0/0/0
ip address 10.1.12.1 255.255.255.0
clock rate 64000
no shutdown
!
router ospf 1
network 10.1.1.0 0.0.0.255 area 0
network 10.1.12.0 0.0.0.255 area 0
!
end
===============================================================================
Router R2
hostname R2
!
interface Loopback2
description Marketing Department
ip address 10.1.2.1 255.255.255.0
ip ospf network point-to-point
!
interface Serial0/0/0
ip address 10.1.12.2 255.255.255.0
no shutdown
!
interface Serial0/0/1
ip address 10.1.23.2 255.255.255.0
clock rate 64000
no shutdown
!
router ospf 1
network 10.1.2.0 0.0.0.255 area 0
network 10.1.12.0 0.0.0.255 area 0
network 10.1.23.0 0.0.0.255 area 23
!
end


======================================================================
Router R3
hostname R3
!
All contents are Copyright © 1992–2010 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.
Page 17 of 18CCNPv6 ROUTE
interface Loopback3
description Accounting Department
ip address 10.1.3.1 255.255.255.0
ip ospf network point-to-point
!
interface Loopback20
description Connection to another AS
ip address 172.20.200.1 255.255.255.0
!
interface Serial0/0/1
ip address 10.1.23.3 255.255.255.0
no shutdown
!
router ospf 1
redistribute connected subnets
network 10.1.3.0 0.0.0.255 area 23
network 10.1.23.0 0.0.0.255 area 23
!
end

However unlike on the lab when I do a : show ip ospf neighbors

I get 172.20.200.1 as neighbor and not 10.1.3.1 as it mentions on the lab on page 155 ( same lab ). Can someone help explain? I am not advertising that network (172....) why is it showing up as neighbor?

I am using 3500 router image on GNS3.

thanks

1 Accepted Solution

Accepted Solutions

Vince
Level 1
Level 1

It may have something to do with the router-id selection process. The router will choose the highest IP of the loopback, or highest IP of physical interface (if loopback is not present) to be it's router-id. It doesn't matter if it is advertised or not.

If you want to use 10.1.3.1, you can use router-id 10.1.3.1 

View solution in original post

1 Reply 1

Vince
Level 1
Level 1

It may have something to do with the router-id selection process. The router will choose the highest IP of the loopback, or highest IP of physical interface (if loopback is not present) to be it's router-id. It doesn't matter if it is advertised or not.

If you want to use 10.1.3.1, you can use router-id 10.1.3.1