9.2.2.8 Lab – Configuring Multi-area OSPFv2 (Instructor Version)
Instructor Note: Red font color or gray highlights indicate text that appears in the instructor copy only.
Topology
Addressing Table
| Device | Interface | IP Address | Subnet Mask |
|---|---|---|---|
| R1 | Lo0 | 209.165.200.225 | 255.255.255.252 |
| Lo1 | 192.168.1.1 | 255.255.255.0 | |
| Lo2 | 192.168.2.1 | 255.255.255.0 | |
| S0/0/0 (DCE) | 192.168.12.1 | 255.255.255.252 | |
| R2 | Lo6 | 192.168.6.1 | 255.255.255.0 |
| S0/0/0 | 192.168.12.2 | 255.255.255.252 | |
| S0/0/1 (DCE) | 192.168.23.1 | 255.255.255.252 | |
| R3 | Lo4 | 192.168.4.1 | 255.255.255.0 |
| Lo5 | 192.168.5.1 | 255.255.255.0 | |
| S0/0/1 | 192.168.23.2 | 255.255.255.252 |
Objectives
Part 1: Build the Network and Configure Basic Device Settings
Part 2: Configure a Multi-area OSPFv2 Network
Background / Scenario
To make OSPF more efficient and scalable, OSPF supports hierarchical routing using the concept of areas. An OSPF area is a group of routers that share the same link-state information in their link-state databases (LSDBs). When a large OSPF area is divided into smaller areas, it is called multi-area OSPF. Multi-area OSPF is useful in larger network deployments to reduce processing and memory overhead.
In the lab, you will configure a multi-area OSPFv2 network.
Note: The routers used with CCNA hands-on labs are Cisco 1941 Integrated Services Routers (ISRs) with Cisco IOS Release 15.2(4)M3 (universalk9 image). Other routers and Cisco IOS versions can be used. Depending on the model and Cisco IOS version, the commands available and output produced might vary from what is shown in the labs. Refer to the Router Interface Summary Table at the end of this lab for the correct interface identifiers.
Note: Make sure that the routers have been erased and have no startup configurations. If you are unsure, contact your instructor.
Instructor Note: Refer to the Instructor Lab Manual for the procedures to initialize and reload devices.
Required Resources
- 3 Routers (Cisco 1941 with Cisco IOS Release 15.2(4)M3 universal image or comparable)
- Console cables to configure the Cisco IOS devices via the console ports
- Serial cables as shown in the topology
Part 1: Build the Network and Configure Basic Device Settings
In Part 1, you will set up the network topology and configure basic settings on the routers.
Step 1: Cable the network as shown in the topology.
Step 2: Initialize and reload the routers as necessary.
Step 3: Configure basic settings for each router.
a. Disable DNS lookup.
b. Configure device name, as shown in the topology.
c. Assign class as the privileged EXEC password.
d. Assign cisco as the console and vty passwords.
e. Configure logging synchronous for the console line.
f. Configure an MOTD banner to warn users that unauthorized access is prohibited.
g. Configure the IP addresses listed in the Addressing Table for all interfaces. DCE interfaces should be configured with a clock rate of 128000. Bandwidth should be set to 128 Kb/s on all serial interfaces.
h. Copy the running configuration to the startup configuration.
Step 4: Verify Layer 3 connectivity.
Use the show ip interface brief command to verify that the IP addressing is correct and that the interfaces are active. Verify that each router can ping their neighbor’s serial interface.
Part 2: Configure a Multi-area OSPFv2 Network
In Part 2, you will configure a multi-area OSPFv2 network with a process ID of 1. All LAN loopback interfaces should be passive.
Step 1: Identify the OSPF router types in the topology.
Identify the Backbone router(s): _______________R1 and R2
Identify the Autonomous System Boundary Router(s) (ASBR): _____________R1
Identify the Area Border Router(s) (ABR): _______________R1 and R2
Identify the Internal router(s): ________________R3
Step 2: Configure OSPF on R1.
a. Configure a router ID of 1.1.1.1 with OSPF process ID of 1.
R1(config)# router ospf 1 R1(config-router)# router-id 1.1.1.1
b. Add the networks for R1 to OSPF.
R1(config-router)# network 192.168.1.0 0.0.0.255 area 1 R1(config-router)# network 192.168.2.0 0.0.0.255 area 1 R1(config-router)# network 192.168.12.0 0.0.0.3 area 0
c. Set LAN loopback interfaces, Lo1 and Lo2, as passive.
R1(config-router)# passive-interface lo1 R1(config-router)# passive-interface lo2 R1(config-router)# exit
d. Create a default route to the Internet using exit interface Lo0.
R1(config)# ip route 0.0.0.0 0.0.0.0 lo0
Note: You may see the “%Default route without gateway, if not a point-to-point interface, may impact performance” message. This is normal behavior if using a Loopback interface to simulate a default route.
e. Configure OSPF to propagate the routes throughout the OSPF areas.
R1(config)# router ospf 1 R1(config-router)# default-information originate
Step 3: Configure OSPF on R2.
a. Configure a router ID of 2.2.2.2 with OSPF process ID of 1.
R2(config)# router ospf 1 R2(config-router)# router-id 2.2.2.2
b. Add the networks for R2 to OSPF. Add the networks to the correct area. Write the commands used in the space below.
____________________________________________________
R2(config-router)# network 192.168.12.0 0.0.0.3 area 0
R2(config-router)# network 192.168.23.0 0.0.0.3 area 3
R2(config-router)# network 192.168.6.0 0.0.0.255 area 3
c. Set all LAN loopback interfaces as passive.
R2(config-router)# passive-interface lo6
Step 4: Configure OSPF on R3.
a. Configure a router ID of 3.3.3.3 with OSPF process ID of 1.
R3(config)# router ospf 1 R3(config-router)# router-id 3.3.3.3
b. Add the networks for R3 to OSPF. Write the commands used in the space below.
_____________________________________________________
R3(config-router)# network 192.168.23.0 0.0.0.3 area 3
R3(config-router)# network 192.168.4.0 0.0.0.255 area 3
R3(config-router)# network 192.168.5.0 0.0.0.255 area 3
c. Set all LAN loopback interfaces as passive.
R3(config-router)# passive-interface lo4 R3(config-router)# passive-interface l05
Step 5: Verify that OSPF settings are correct and adjacencies have been established between routers.
a. Issue the show ip protocols command to verify OSPF settings on each router. Use this command to identify the OSPF router types and to determine the networks assigned to each area.
R1# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "ospf 1"
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Router ID 1.1.1.1
It is an area border and autonomous system boundary router
Redistributing External Routes from,
Number of areas in this router is 2 . 2 normal 0 stub 0 nssa
Maximum path: 4
Routing for Networks:
192.168.1.0 0.0.0.255 area 1
192.168.2.0 0.0.0.255 area 1
192.168.12.0 0.0.0.3 area 0
Passive Interface(s):
Loopback1
Loopback2
Routing Information Sources:
Gateway Distance Last Update
2.2.2.2 110 00:01:45
Distance: (default is 110)
R2# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "ospf 1"
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Router ID 2.2.2.2
It is an area border router
Number of areas in this router is 2 . 2 normal 0 stub 0 nssa
Maximum path: 4
Routing for Networks:
192.168.6.0 0.0.0.255 area 3
192.168.12.0 0.0.0.3 area 0
192.168.23.0 0.0.0.3 area 3
Passive Interface(s):
Loopback6
Routing Information Sources:
Gateway Distance Last Update
3.3.3.3 110 00:01:20
1.1.1.1 110 00:10:12
Distance: (default is 110)
R3# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "ospf 1"
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Router ID 3.3.3.3
Number of areas in this router is 1 . 1 normal 0 stub 0 nssa
Maximum path: 4
Routing for Networks:
192.168.4.0 0.0.0.255 area 3
192.168.5.0 0.0.0.255 area 3
192.168.23.0 0.0.0.3 area 3
Passive Interface(s):
Loopback4
Loopback5
Routing Information Sources:
Gateway Distance Last Update
1.1.1.1 110 00:07:46
2.2.2.2 110 00:07:46
Distance: (default is 110)
What is the OSPF router type for each router?
R1: ____________________________________
R2: ____________________________________
R3: ____________________________________
R1 – ABR and ASBR
R2 – ABR
R3 – No special OSPF router type
b. Issue the show ip ospf neighbor command to verify that OSPF adjacencies have been established between routers.
R1# show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 2.2.2.2 0 FULL/ - 00:00:34 192.168.12.2 Serial0/0/0 R2# show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 1.1.1.1 0 FULL/ - 00:00:36 192.168.12.1 Serial0/0/0 3.3.3.3 0 FULL/ - 00:00:36 192.168.23.2 Serial0/0/1 R3# show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 2.2.2.2 0 FULL/ - 00:00:38 192.168.23.1 Serial0/0/1
c. Issue the show ip ospf interface brief command to display a summary of interface route costs.
R1# show ip ospf interface brief Interface PID Area IP Address/Mask Cost State Nbrs F/C Se0/0/0 1 0 192.168.12.1/30 781 P2P 1/1 Lo1 1 1 192.168.1.1/24 1 LOOP 0/0 Lo2 1 1 192.168.2.1/24 1 LOOP 0/0 R2# show ip ospf interface brief Interface PID Area IP Address/Mask Cost State Nbrs F/C Se0/0/0 1 0 192.168.12.2/30 781 P2P 1/1 Lo6 1 3 192.168.6.1/24 1 LOOP 0/0 Se0/0/1 1 3 192.168.23.1/30 781 P2P 1/1 R3# show ip ospf interface brief Interface PID Area IP Address/Mask Cost State Nbrs F/C Lo4 1 3 192.168.4.1/24 1 LOOP 0/0 Lo5 1 3 192.168.5.1/24 1 LOOP 0/0 Se0/0/1 1 3 192.168.23.2/30 781 P2P 1/1
Reflection
What are three advantages for designing a network with multi-area OSPF?
____________________________________________________
1. Smaller routing tables. 2. Reduced link-state update overhead. 3. Reduced frequency of SPF calculations.
Router Interface Summary Table
| Router Interface Summary | ||||
|---|---|---|---|---|
| Router Model | Ethernet Interface #1 | Ethernet Interface #2 | Serial Interface #1 | Serial Interface #2 |
| 1800 | Fast Ethernet 0/0 (F0/0) | Fast Ethernet 0/1 (F0/1) | Serial 0/0/0 (S0/0/0) | Serial 0/0/1 (S0/0/1) |
| 1900 | Gigabit Ethernet 0/0 (G0/0) | Gigabit Ethernet 0/1 (G0/1) | Serial 0/0/0 (S0/0/0) | Serial 0/0/1 (S0/0/1) |
| 2801 | Fast Ethernet 0/0 (F0/0) | Fast Ethernet 0/1 (F0/1) | Serial 0/1/0 (S0/1/0) | Serial 0/1/1 (S0/1/1) |
| 2811 | Fast Ethernet 0/0 (F0/0) | Fast Ethernet 0/1 (F0/1) | Serial 0/0/0 (S0/0/0) | Serial 0/0/1 (S0/0/1) |
| 2900 | Gigabit Ethernet 0/0 (G0/0) | Gigabit Ethernet 0/1 (G0/1) | Serial 0/0/0 (S0/0/0) | Serial 0/0/1 (S0/0/1) |
| Note: To find out how the router is configured, look at the interfaces to identify the type of router and how many interfaces the router has. There is no way to effectively list all the combinations of configurations for each router class. This table includes identifiers for the possible combinations of Ethernet and Serial interfaces in the device. The table does not include any other type of interface, even though a specific router may contain one. An example of this might be an ISDN BRI interface. The string in parenthesis is the legal abbreviation that can be used in Cisco IOS commands to represent the interface. | ||||
Device Configs – Final
Router R1
R1# show run Building configuration... Current configuration : 2062 bytes ! version 15.2 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname R1 ! boot-start-marker boot-end-marker ! enable secret 4 06YFDUHH61wAE/kLkDq9BGho1QM5EnRtoyr8cHAUg.2 ! no aaa new-model memory-size iomem 15 ! ip cef ! no ip domain lookup no ipv6 cef multilink bundle-name authenticated ! interface Loopback0 ip address 209.165.200.225 255.255.255.252 ! interface Loopback1 ip address 192.168.1.1 255.255.255.0 ! interface Loopback2 ip address 192.168.2.1 255.255.255.0 ! interface Embedded-Service-Engine0/0 no ip address shutdown ! interface GigabitEthernet0/0 no ip address shutdown duplex auto speed auto ! interface GigabitEthernet0/1 no ip address shutdown duplex auto speed auto ! interface Serial0/0/0 bandwidth 128 ip address 192.168.12.1 255.255.255.252 clock rate 128000 ! interface Serial0/0/1 no ip address shutdown ! router ospf 1 router-id 1.1.1.1 passive-interface Loopback1 passive-interface Loopback2 network 192.168.1.0 0.0.0.255 area 1 network 192.168.2.0 0.0.0.255 area 1 network 192.168.12.0 0.0.0.3 area 0 default-information originate ! ip forward-protocol nd ! no ip http server no ip http secure-server ! ip route 0.0.0.0 0.0.0.0 Loopback0 ! control-plane ! ! banner motd @ Unauthorized Access is Prohibited! @ ! line con 0 password cisco logging synchronous login line aux 0 line 2 no activation-character no exec transport preferred none transport input all transport output pad telnet rlogin lapb-ta mop udptn v120 ssh stopbits 1 line vty 0 4 password cisco login transport input none ! scheduler allocate 20000 1000 ! end
Router R2
R2# show run Building configuration... Current configuration : 1905 bytes ! version 15.2 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname R2 ! boot-start-marker boot-end-marker ! enable secret 4 06YFDUHH61wAE/kLkDq9BGho1QM5EnRtoyr8cHAUg.2 ! no aaa new-model memory-size iomem 15 ! ip cef ! no ip domain lookup no ipv6 cef multilink bundle-name authenticated ! interface Loopback6 ip address 192.168.6.1 255.255.255.0 ! interface Embedded-Service-Engine0/0 no ip address shutdown ! interface GigabitEthernet0/0 no ip address shutdown duplex auto speed auto ! interface GigabitEthernet0/1 no ip address shutdown duplex auto speed auto ! interface Serial0/0/0 bandwidth 128 ip address 192.168.12.2 255.255.255.252 ! interface Serial0/0/1 bandwidth 128 ip address 192.168.23.1 255.255.255.252 clock rate 128000 ! router ospf 1 router-id 2.2.2.2 passive-interface Loopback6 network 192.168.6.0 0.0.0.255 area 3 network 192.168.12.0 0.0.0.3 area 0 network 192.168.23.0 0.0.0.3 area 3 ! ip forward-protocol nd ! no ip http server no ip http secure-server ! control-plane ! banner motd @ Unauthorized Access is Prohibited! @ ! line con 0 password cisco logging synchronous login line aux 0 line 2 no activation-character no exec transport preferred none transport input all transport output pad telnet rlogin lapb-ta mop udptn v120 ssh stopbits 1 line vty 0 4 password cisco login transport input all ! scheduler allocate 20000 1000 ! end
Router R3
R3# show run Building configuration... Current configuration : 1958 bytes ! version 15.2 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname R3 ! boot-start-marker boot-end-marker ! enable secret 4 06YFDUHH61wAE/kLkDq9BGho1QM5EnRtoyr8cHAUg.2 ! no aaa new-model memory-size iomem 15 ! ip cef ! no ip domain lookup no ipv6 cef ! multilink bundle-name authenticated ! interface Loopback4 ip address 192.168.4.1 255.255.255.0 ! interface Loopback5 ip address 192.168.5.1 255.255.255.0 ! interface Embedded-Service-Engine0/0 no ip address shutdown ! interface GigabitEthernet0/0 no ip address shutdown duplex auto speed auto ! interface GigabitEthernet0/1 no ip address shutdown duplex auto speed auto ! interface Serial0/0/0 no ip address shutdown clock rate 2000000 ! interface Serial0/0/1 bandwidth 128 ip address 192.168.23.2 255.255.255.252 ! router ospf 1 router-id 3.3.3.3 passive-interface Loopback4 passive-interface Loopback5 network 192.168.4.0 0.0.0.255 area 3 network 192.168.5.0 0.0.0.255 area 3 network 192.168.23.0 0.0.0.3 area 3 ! ip forward-protocol nd ! no ip http server no ip http secure-server ! control-plane ! banner motd @ Unauthorized Access is Prohibited! @ ! line con 0 password cisco logging synchronous login line aux 0 line 2 no activation-character no exec transport preferred none transport input all transport output pad telnet rlogin lapb-ta mop udptn v120 ssh stopbits 1 line vty 0 4 password cisco login transport input none ! scheduler allocate 20000 1000 ! end