6.1-Objectives and Background

Lab 6 – OSPFv2 Route Summarization and Filtering

Topology

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Addressing Table

Device	Interface	IPv4 Address
R1	G0/0	172.16.0.2/30
	G0/1	10.10.0.1/30
R2	G0/0	172.16.0.1/30
	G0/1	172.16.1.1/30
R2	Lo0	209.165.200.225/27
R3	G0/1	172.16.1.2/30
	G0/2	10.10.4.1/30
D1	G0/1	10.10.0.2/30
	G0/3	10.10.1.1/24
	Lo2	10.10.2.1/24
	Lo3	10.10.3.1/24
D2	G0/2	10.10.4.2/30
	G0/3	10.10.5.1/24
	Lo16	10.10.16.1/24
	Lo17	10.10.17.1/24
	Lo18	10.10.18.1/24
	Lo19	10.10.19.1/24
	Lo20	10.10.20.1/24
	Lo21	10.10.21.1/24
	Lo22	10.10.22.1/24
	Lo23	10.10.23.1/24
PC1	NIC	10.10.1.10/24
PC2	NIC	10.10.5.10/24

Objectives

Part 1: Build the Network, Configure Basic Device Settings and Routing

Part 2: OSPFv2 Route Summarization

Part 3: OSPFv2 Route Filtering

Background / Scenario

Areas make OSPF more scalable and increase efficiency. Consider a large multinational organization with a thousand OSPF routers. If all routers were in a single area, the information contained in their LSDB would be overwhelming. Segmenting the OSPF domain into multiple areas reduces the size of the LSDB for each area, making SPF tree calculations faster, and decreasing LSDB flooding between routers when a link flaps.

To make OSPF even more scalable and efficient, network routes can be summarized and advertised in other areas. As well, specific route filtering can be used to provide more precise control on route propagation.

In this lab, you will configure route summarization and route filtering in a multiarea OSPF version 2 network. This lab was specifically designed to use three routers and two Layer 3 switches. To help visualize the potential of summarization and route filtering, additional loopback interfaces will be configured to simulate LANs and create larger routing tables.

Note: This lab is an exercise in developing, deploying, and verifying how OSPF route summarization and filtering operates and does not reflect networking best practices.

Note: The router used with this CCNP hands-on lab is a Cisco 4221and the two Layer 3 switches are Catalyst 3560 switches. Other routers and Layer 3 switches and Cisco IOS versions can be used. Depending on the model and Cisco IOS version, the commands available and the output produced might vary from what is shown in the labs.

Note: Ensure that the routers and switches have been erased and have no startup configurations. If you are unsure contact your instructor.

Required Resources

3 Routers (Cisco 4221 with Cisco IOS XE Release 16.9.4 universal image or comparable)
2 Switches (Cisco 3650 with Cisco IOS XE Release 16.9.4 universal image or comparable)
2 PCs (Windows with terminal emulation program, such as Tera Term)
Console cables to configure the Cisco IOS devices via the console ports

Ethernet cables as shown in the topology