Chapter 3: Network Routing
Exam Objectives
Describing the types of network routes and knowing when to use them
Describing routing and routed protocols, their characteristics, and purpose
Describing routing decision criteria
Distinguishing distance vector routing from link-state routing
Describing route updates and convergence
Describing routing administrative distance
Describing common routing protocol metrics
Describing the general process to enable and configure a routing protocol
Read this chapter to find out about Layer 3 routing. Routers route data packets between networks. Routers do the following:
♦ Manage routing protocols
♦ Build routing tables using routing protocols
♦ Route packets using routed protocols and routing tables
♦ Maintain routing tables
Introducing Network Routes
A network route is a data transmission path through one or more networks between two end nodes. The end nodes can be any computer device that supports IP connectivity, such as computer hosts, IP phones, digital video consoles, and smartphones.
More than one route can exist between two end nodes. The main purpose of a router is to find the best route to reach a destination node. The best route is calculated according to route metrics: the cost in time and resources to send a data packet over that route.
More than one router can exist in the data transmission path between the sending and the receiving nodes. For example, when you connect to an Internet Web site from your home computer, your computer ...
