Concept Exercise Chapter 11 Name:
Date: Class:
Cisco Exercises - Semester 2 - Networking Fundamentals
Chapter11 Routing
Introduction
Which path should traffic take through the cloud of networks? Path determination occurs at Layer 3 of the OSI reference model, the network layer. The path determination function enables a router to evaluate the available paths to a destination and to establish the preferred handling of a packet.
Routing services use network topology information when evaluating network paths. This information can be configured by the network administrator or collected through dynamic processes running in the network.
The network layer interfaces to networks and provides best-effort, end-to-end packet delivery services to its user, the transport layer. The network layer sends packets from the source network to the destination network based on the IP routing table.
After the router determines which path to use, it can proceed with forwarding the packet: It takes the packet it accepted on one interface and forwards it to another interface or port that reflects the best path to the packet's destination.
Concept Questions
Demonstrate you knowledge of these concepts by answering the following questions in the space provided.
Internetworking functions of the network layer include network addressing and best path selection for traffic. What is best path selection?
In network addressing, one part of the address is used to identify the path used by the router and the other is used for ports or devices on the network. Which part of the address is used to identify the path used by the router?
Routed protocols allow routers to direct user traffic, and routing protocols work between routers to maintain path tables. Explain this key difference.
Network discovery for distance-vector routing involves exchange of routing tables; problems can include slow convergence. What other problems can occur as a result of exchanging routing tables?
For link-state routing, routers calculate the shortest paths to other routers; problems can include inconsistent updates. What other problems might occur with link-state routing?
Balanced hybrid routing uses attributes of both link-state and distance-vector routing, and can apply paths to several protocols. What advantages does balance hybrid routing offer?