Prerequisites: CCNP level skills.
In the next few labs I am going to use the following topology.
Topology
Pic. 1 – OSPF Multi-Area Topology.
Workflow
- Get familiar with the topology and the ‘Task List’.
- Answer the questions.
- Enable IP addresses as per the topology diagram (pic. 1).
- Check layer 3 reachability between all routers (point to point reachability since there is no OSPF enabled yet).
- Enable OSPF as per topology diagram (pic. 1) using the Task List below.
- Ensure full reachability between all IP addresses in the network presented (pic. 1).
Task List
- All loopback addresses should be advertised with their configured network mask (/24).
- All interfaces of R3 must belong to the backbone area.
- Loopback0 interfaces of R1 and R2 must belong to the area 0.
- F1/0 interfaces of R1 and R2 must belong the the area 1. Area 1 should be a normal area in this lab.
- R1 should be the DR, and R2 should be the BDR on the Ethernet Segment (10.1.123.0/24).
- All interfaces of R4 should operate in the area 1. The Loopback addresses should be advertised with their configured network mask.
Questions
- What are the reasons to use multi-area rather than single area OSPF design?
- What are the OSPF router types
- What is ABR and its role?
- What is ASBR and its role?
- What are the types of LSAs and what they describe?
- What are the OSPF area types and which LSAs do they maintain?
Video Note – The answers.
http://www.youtube.com/watch?v=8u6-_mkc0-4
Lab Solution
R1 Configuration:
!
interface Loopback0
ip address 172.16.101.1 255.255.255.0
ip ospf network point-to-point
!
ip address 172.16.101.1 255.255.255.0
ip ospf network point-to-point
!
interface FastEthernet1
ip address 10.1.124.1
ip ospf priority 20
!
ip address 10.1.124.1
ip ospf priority 20
!
interface Serial0/1
ip address 10.1.13.1 255.255.255.0
serial restart-delay 0
ip address 10.1.13.1 255.255.255.0
serial restart-delay 0
!
router ospf 1
router-id 1.1.1.1
log-adjacency-changes
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
!
router-id 1.1.1.1
log-adjacency-changes
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
!
R2 Configuration:
!
interface Loopback0
ip address 172.16.102.2 255.255.255.0
ip ospf network point-to-point
ip address 172.16.102.2 255.255.255.0
ip ospf network point-to-point
!
interface FastEthernet1/0
ip address 10.1.124.2 255.255.255.0
ip ospf priority 10
!
ip address 10.1.124.2 255.255.255.0
ip ospf priority 10
!
interface Serial0/2
ip address 10.1.23.2 255.255.255.0
serial restart-delay 0
ip address 10.1.23.2 255.255.255.0
serial restart-delay 0
!
router ospf 1
router-id 2.2.2.2
log-adjacency-changes
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
!
router-id 2.2.2.2
log-adjacency-changes
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
!
R3 Configuration:
!
interface Loopback0
ip address 172.16.103.3 255.255.255.0
ip ospf network point-to-point
!
ip address 172.16.103.3 255.255.255.0
ip ospf network point-to-point
!
interface Loopback1
ip address 172.16.133.3 255.255.255.0
ip ospf network point-to-point
!
ip address 172.16.133.3 255.255.255.0
ip ospf network point-to-point
!
interface Serial0/1
ip address 10.1.13.3 255.255.255.0
serial restart-delay 0
ip address 10.1.13.3 255.255.255.0
serial restart-delay 0
!
interface Serial0/2
ip address 10.1.23.3 255.255.255.0
!
ip address 10.1.23.3 255.255.255.0
!
router ospf 1
router-id 3.3.3.3
log-adjacency-changes
network 0.0.0.0 255.255.255.255 area 0
!
router-id 3.3.3.3
log-adjacency-changes
network 0.0.0.0 255.255.255.255 area 0
!
R4 Configuration:
!
interface Loopback0
ip address 172.16.104.4 255.255.255.0
ip ospf network point-to-point
!
ip address 172.16.104.4 255.255.255.0
ip ospf network point-to-point
!
interface Loopback1
ip address 172.16.144.4 255.255.255.0
ip ospf network point-to-point
!
ip address 172.16.144.4 255.255.255.0
ip ospf network point-to-point
!
interface FastEthernet1/0
ip address 10.1.124.4 255.255.255.0
!
ip address 10.1.124.4 255.255.255.0
!
router ospf 1
router-id 4.4.4.4
log-adjacency-changes
network 0.0.0.0 255.255.255.255 area 1
router-id 4.4.4.4
log-adjacency-changes
network 0.0.0.0 255.255.255.255 area 1
Verification
Pic. 1
Pic. 2
Pic. 3
Pic. 4