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?