CCNA3 - Lab 6.2.4 Part A: Configuring and Verifying Point-to-Point OSPF

Step 1: Connect the equipment

1. Connect the Fa0/0 interface of each router to the Fa0/1 interface of each switch using a straightthrough cable.
2. Connect each host to the Fa0/2 switch port of each switch using a straight-through cable.
3. Connect serial cables from each router to the other router as shown in the topology.

Step 2: Perform basic configurations on the routers

1. Connect a PC to the console port of the router to perform configurations using a terminal emulation program.
2. On all routers, configure the hostname, passwords, and message-of-the-day banner and disable DNS lookups according to the addressing table and topology diagram.

Step 3: Configure the router interfaces

Step 4: Verify IP addressing and interfaces

1. Use the show ip interface brief or the show protocols command to verify that the IP addressing is correct and that the interfaces are active.
2. After all interfaces are verified, be sure to save the running configuration to the NVRAM of the router.

Step 5: Configure Ethernet interfaces of PC1, PC2, and PC3

1. Configure the Ethernet interfaces of PC1, PC2, and PC3 with the IP addresses and default gateways from the addressing table.
2. Test the PC configuration by pinging the default gateway from each PC.

Step 6: Configure OSPF on Router 1

1. Configure OSPF on the R1 router. Enter a process ID of 1 for the process-ID parameter. R1(config)#router ospf 1
2. Configure the network statement for the LAN. When you are in the Router OSPF configuration submode, configure the LAN 172.16.1.16/28 to be included in the OSPF updates that are sent out of R1. Use an area ID of 0 for the OSPF area-id parameter. Zero will be used for the OSPF area ID in all network statements in this topology.

R1(config-router)#network 172.16.1.16 0.0.0.15 area 0

1. Configure the router to advertise the 192.168.10.0/30 network attached to the Serial 0/0/0 interface.

R1(config-router)#network 192.168.10.0 0.0.0.3 area 0

1. Configure the router to advertise the 192.168.10.4/30 network attached to the Serial 0/0/1 interface. R1(config-router)#network 192.168.10.4 0.0.0.3 area 0
2. Return to privileged EXEC mode and save the configuration.

Step 7: Configure OSPF on the R2 router

1. Enable OSPF routing on the R2 router using the router ospf command. Use a process ID of 1.

R2(config)#router ospf 1

1. Configure the router to advertise the LAN network 10.10.10.0/24 in the OSPF updates.

R2(config-router)#network 10.10.10.0 0.0.0.255 area 0

Step 8: Configure OSPF on the R3 router

Configure OSPF on the R3 router using the router ospf and network commands. Use a process ID of 1. Configure the router to advertise the three directly connected networks. When you are finished, return to privileged EXEC mode.

Step 9: Configure OSPF router IDs

1. The OSPF router ID is used to uniquely identify the router in the OSPF routing domain. A router ID is an IP address. Cisco routers derive the router ID in one of three ways, and with the following precedence:
2. Examine the current router IDs in the topology.
3. The router ID can also be seen in the output of the show ip protocols, show ip ospf, and show ip ospf interfaces commands.

Step 10: Verify OSPF operation

1. On the R1 router, use the show ip ospf neighbor command to view the information about the
2. On the R1 router, use the show ip protocols command to view information about the routing protocol operation.

Step 11: Examine OSPF routes in the routing tables

View the routing table on the R1 router. OSPF routes are denoted in the routing table with an O.

Step 12: Configure OSPF cost

1. Use the show ip route command on the R1 router to view the OSPF cost to reach the 10.10.10.0/24 network.
2. Use the show interfaces serial0/0/0 command on the R1 router to view the bandwidth of the Serial 0/0/0 interface.

Step 13: Reflection

What are some advantages of using OSPF as a routing protocol? Jawaban: supports VLSM and CIDR, uses cost metrics to choose the best path, and each router has a complete picture of the entire network.