Lab 5 - OSPF in Point-to-Multipoint Non-broadcast

Prerequisites: CCNP level skills.

Cisco IOS OSPF modes:

1. Point-to-point (Cisco)
2. Broadcast (Cisco)
3. Non-broadcast (RFC 2328)
4. Point-to-multipoint (RFC 2328)
5. Point-to-multipoint non-broadcast (Cisco)

Topology

Pic. 1 - Topology Diagram.

Icons designed by: Andrzej Szoblik - http://www.newo.pl

Workflow

1. Get familiar with the topology.
2. Read the 'Task List'.
3. Read the 'Questions' and provide the answers BEFORE configuring the routers.
4. Configure the lab according to the 'Task List' .
5. Compare the answers (step 3) with the lab results.

Task List

• Configure IP addresses as per topology diagram and use encapsulation Frame-Relay on S0/0 interfaces.
• Make sure that you use only DLCIs specified in the topology diagram (pic. 1) and routers do not learn any other other DLCIs dynamically.
• Assume that pseudo broadcast is not supported.
• Configure OSPF with all links in area 0. Make sure that R2 can ping R3's loopback0 and S0/0 interfaces (no additional layer 3 to layer 2 mappings).

Questions

1. What is the behavior of OSPF point-to-multipoint non-broadcast mode compared to non-broadcast on Frame-Relay links?
2. How does point-to-multipoint mode differ from point-to-multipoint non-broadcast OSPF mode?
3. What are the default hello/dead interval timers on point-to-multipoint non-broadcast links?
4. What is going to be the next-hop address on R2 for 172.16.103.0/24 using point-to-multipoint links? Why?

Lab Solution

Note!
Lab is similar to Lab 4 (previous post). The only difference is the mandatory 'neighbor' statement on R1. Except for that, the behavior is just like on point-to-multipoint networks.

R1 Configuration:

!

interface loopback0

 ip address 172.16.101.1 255.255.255.0
 ip ospf network point-to-point
!

interface Serial0/0
 ip address 10.1.1.1 255.255.255.0
 encapsulation frame-relay
 ip ospf network point-to-multipoint non-broadcast
 frame-relay map ip 10.1.1.2 102
 frame-relay map ip 10.1.1.3 103
 no frame-relay inverse-arp
!

router ospf 1
 router-id 1.1.1.1
 log-adjacency-changes
 network 10.1.1.1 0.0.0.0 area 0
 network 172.16.101.1 0.0.0.0 area 0
 neighbor 10.1.1.3
 neighbor 10.1.1.2
!

R2 Configuration:

!

interface loopback0

 ip address 172.16.102.2 255.255.255.0
 ip ospf network point-to-point
!

interface Serial0/0
 ip address 10.1.1.2 255.255.255.0
 encapsulation frame-relay
 ip ospf network point-to-multipoint non-broadcast
 frame-relay map ip 10.1.1.1 201
 no frame-relay inverse-arp
!

router ospf 1
 router-id 2.2.2.2
 log-adjacency-changes
 network 10.1.1.2 0.0.0.0 area 0
 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
!

interface Serial0/0
 ip address 10.1.1.3 255.255.255.0
 encapsulation frame-relay
 ip ospf network point-to-multipoint non-broadcast
 frame-relay map ip 10.1.1.1 301
 no frame-relay inverse-arp
!

router ospf 1
 router-id 3.3.3.3
 log-adjacency-changes
 network 10.1.1.3 0.0.0.0 area 0
 network 172.16.103.3 0.0.0.0 area 0
!

Verification

Note!
The verification steps as per Lab04.