DEVNET.

Lab 7 – OSPF Authentication

Prerequisites: CCNP level skills.

Note!
Routers use OSPF configuration from the lab 6.

Topology

Pic. 1 – OSPF Multi-Area Topology.
Task List

Configuring authentication use the password: ‘cisco’.

Task 1
All loopback addresses should be advertised with their configured network mask (/24).

Task 2
Configure the strongest OSPF authentication between R2 and R3. On R3, enable authentication under the routing process (config-router) but make sure there is no OSPF authentication between R1 and R3.

Task 3
Enable Simple Password OSPF authentication in the area 1. R4 should have OSPF authentication enabled on F1/0 interface but not in the ‘config-router’ context. 

Lab Solution

Task 1
On all loopback interfaces (all routers should already be configured with this as per lab 6):

All loopback addresses should be advertised with their configured network mask (/24). 

!
interface loopbackX

ip ospf network point-to-point
!

Task 2

Configure the strongest OSPF authentication between R2 and R3. On R3, enable authentication under the routing process (config-router) but make sure there is no OSPF authentication between R1 and R3.

R2 Configuration:

!
interface Serial0/2
ip address 10.1.23.2 255.255.255.0
ip ospf authentication message-digest
ip ospf message-digest-key 1 md5 cisco
!

R3 Configuration:

!
router ospf 1
router-id 3.3.3.3
log-adjacency-changes
area 0 authentication message-digest
network 0.0.0.0 255.255.255.255 area 0
!
interface Serial0/1
ip address 10.1.13.3 255.255.255.0
ip ospf authentication null
!
interface Serial0/2
ip address 10.1.23.3 255.255.255.0
ip ospf message-digest-key 1 md5 cisco
!

Task 3

Enable Simple Password OSPF authentication in the area 1. R4 should have OSPF authentication enabled on F1/0 interface but not in the ‘config-router’ context.

R1 Configuration:

!
router ospf 1
router-id 1.1.1.1
log-adjacency-changes
area 1 authentication
network 10.1.13.1 0.0.0.0 area 0
network 10.1.124.1 0.0.0.0 area 1
network 172.16.101.1 0.0.0.0 area 0
!
interface FastEthernet1/0
ip address 10.1.124.1 255.255.255.0
ip ospf authentication-key cisco
ip ospf priority 20
!

R2 Configuration:

!
router ospf 1
router-id 2.2.2.2
log-adjacency-changes
area 1 authentication
network 10.1.23.2 0.0.0.0 area 0
network 10.1.124.2 0.0.0.0 area 1
network 172.16.102.2 0.0.0.0 area 0
!
interface FastEthernet1/0
ip address 10.1.124.2 255.255.255.0
ip ospf authentication-key cisco
ip ospf priority 10
!

R4 Configuration:

!
router ospf 1
router-id 4.4.4.4
log-adjacency-changes
network 0.0.0.0 255.255.255.255 area 1
!
interface FastEthernet1/0
ip address 10.1.124.4 255.255.255.0
ip ospf authentication
ip ospf authentication-key cisco
!

Verification

All routers should be fully adjacent with their neighbors (should be checked after every task)!

Share:

Share on facebook
Facebook
Share on twitter
Twitter
Share on linkedin
LinkedIn

Leave a Reply

Your email address will not be published. Required fields are marked *

Become a member

Full Access to 739 Lessons. New Lessons Added Every Week!

Awesome Deal! Get 2 Months for FREE!

No Obligations. Cancel At Any Time!