Chapter 8 - The Network Layer

Question 1

What Services Does the Network Layer Provide?

Answer 1

• to exchange packets over the network between identified end devices
• uses addressing, encapsulation, routing and de-encapsulation to accomplish end-to-end transport
• directs packets between hosts; either itself, local or remote

Question 2

How Does a Routing Table Work?

Answer 2

• it stores information about the directly connected routes, the remote routes and the default routes
• when a packet arrives on a router interface, the destination address in the header is examined and a match is attempted to be found - this is the exit interface

Question 3

How Can Networks Be Learnt About?

Answer 3

• Manually: entered into the routing table using static routes
• Dynamically: remote routes are automatically learned using a dynamic routing protocol (DHCP, OSPF, EIGRP)