CCNA Exploration - Routing Protocols and Concepts
2 Static Routing
2.0 Chapter Introduction
2.0.1 Chapter Introduction
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Chapter Introduction
Routing is at the core of every data network, moving information across an internetwork from source to destination. Routers are the devices responsible for the transfer of packets from one network to the next.
As we learned in the previous chapter, routers learn about remote networks either dynamically using routing protocols or manually using static routes. In many cases routers use a combination of both dynamic routing protocols and static routes. This chapter focuses on static routing.
Static routes are very common and do not require the same amount of processing and overhead as we will see with dynamic routing protocols.
In this chapter, we will follow a sample topology as we configure static routes and learn troubleshooting techniques. In the process, we will examine several key IOS commands and the results they display. We will also introduce the routing table using both directly connected networks and static routes.
As you work through the Packet Tracer activities associated with these commands, take the time to experiment with the commands and examine the results. Reading the routing tables will soon become second nature.
2.0.1 - Chapter Introduction
The diagram depicts the front panel of various Cisco routers and a list of chapter objectives. In this chapter you will learn to:
- Define the general role a router plays in networks.
- Describe the directly connected networks and the different router interfaces.
- Examine directly connected networks in the routing table and use the CDP protocol.
- Describe static routes with exit interfaces.
- Describe summary and default routes.
- Examine how packets get forwarded when using static routes.
- Identify how to manage and troubleshoot static routes.
2.1 Routers and Network
2.1.1 Role of the Router
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Role of the Router
The router is a special-purpose computer that plays a key role in the operation of any data network. Routers are primarily responsible for interconnecting networks by:
Determining the best path to send packets
Forwarding packets toward their destination
Routers perform packet forwarding by learning about remote networks and maintaining routing information. The router is the junction or intersection that connects multiple IP networks. The routers primary forwarding decision is based on Layer 3 information, the destination IP address.
The router's routing table is used to find the best match between the destination IP of a packet and a network address in the routing table. The routing table will ultimately determine the exit interface to forward the packet and the router will encapsulate that packet in the appropriated data link frame for that outgoing interface.
2.1.1 - Role of the Router
The diagram depicts the role of the router. A photograph of a router is shown with arrows pointing to routers in a topology.
