Chapter 10

Question 1

what are the two routing protocols used on internetworks?

Answer 1

Internal gateway protocol (IGP) and External gateway protocol (EGP). p.299

Question 2

what is the function of IGPs?

Answer 2

They are used to exchange routing info with routers in the same autonomous system. p. 299

Question 3

Define Autonomous System.

Answer 3

A collection of networks under a common administrative domain which simply means that all routers sharing the same routing table info are int he same AS. EGPs are used to communicate between multiple AS. p. 299

Question 4

Give an example of an EGP.

Answer 4

Border Gateway Protocol (BGP) p. 299

Question 5

Define Administrative Distance.

Answer 5

Is used to rate the trustworthiness of routing information received on one router form its neighboring router. Zero is the most trusted route 255 is the least. p. 300

Question 6

what does an admistrative distance of 255 mean?

Answer 6

No traffic is allowed. p. 300

Question 7

What happens if there are two advertised routes with the same administrative distance?

Answer 7

The routing protocol uses hop count or the amount of bandwidth on the lines to find the best path to the remote network. The route with the lowest metric will be on the routing table. p. 300

Question 8

what happens if two advertised routes have the same AD and the same metrics?

Answer 8

the routing protocol will load balance to the remote network. p. 300

Question 9

define load balancing.

Answer 9

a router sends packets down each link to test for the best one. p. 300

Question 10

what is the default AD to the Conected Interface route source?

Answer 10

0 p. 301

Question 11

what is the default AD to the Static route, route source?

Answer 11

1 p. 301

Question 12

what is the default AD to the External BGP route source?

Answer 12

20 p. 301

Question 13

what is the default AD to the Internal EIGRP route source?

Answer 13

90 p. 301

Question 14

what is the default AD to the IRGP route source?

Answer 14

100 p. 301

Question 15

what are three classes of routing protocols?

Answer 15

Distance vector
Link state
Hybrid p. 303

Question 16

what does the distance vector protocol do?

Answer 16

Finds the best path to a remote network by judging distance. Each time a packet goes through a router it equals a hop, the route with the fewest hops is chosen. p. 302

Question 17

What type of protocols are RIP, RIPv2 and Intterior Gateway Routing Protocol (IRGP)?

Answer 17

Distance vector protocols. p. 302

Question 18

What is a Link State Protocol?

Answer 18

AKA shortest path first protocol. The routers create three seperate tables. One keeps track of dirctly attached neighbors or determines the topology of the entire network. p. 303

Question 19

what are some common Link State Routing Protocols?

Answer 19

OSPF and IS-IS are IP routing protocols that are link state. p. 303

Question 20

What is a Hybrid Routing Protocol?

Answer 20

Uses aspects of both distance vetor and link state. p. 303

Question 21

What are some common Hybrid protocols?

Answer 21

EIGRP and BGP p.303

Question 22

Describe routing by rumor.

Answer 22

When a distance vector routing algorithm pases its complete routing table contents to neighboring routers the routers take this information and compares it with its own information. It does so without verifying the neighbors are telling the truth. p. 303

Question 23

Describe Routing Information Protocol (RIP).

Answer 23

It is a true distance vector routing protocol. It send s the complete roting table out to all active interfaces every 30 seconds. It uses a hop count to determine the best way tot a remote network. p. 305

Question 24

what are some differences between RIP and RIPv2?

Answer 24

RIPv2 is classless, uses multicast, supports VLSM networks, allows for MD5 authentication and supports discontiguious networks. p. 306

Question 25

Describe EIGRP.

Answer 25

It is considered a Hybrid protocol because it uses characteristics of both distance vector and link state protocols. It is a classless enhanced distance vector protocol. It uses the concept of an autonomous system to describe the set of contiguous routers that run the same routing protocol and share routing information. It includes the subnet mask in its route updates.