Week 4: Intro to Routing

Question 1

What are Routed Protocols?

Answer 1

Protocols that can carry network layer information

Question 2

What are Routing Protocols?

Answer 2

Protocols used by routers to make path determination choices & to share those choices with other routers

Question 3

List some characteristics of Routed Protocols

Answer 3

Have packet headers that contain network layer addresses

Developed to support network consisting of multiple networks or subnetworks

Question 4

List some characteristics of Routing Protocols

Answer 4

Performs dynamic route selection/decision

Question 5

List some examples of Routed Protocols

Answer 5

IP, IPX, AppleTalk

Question 6

List some Examples of Routing Protocols

Answer 6

RIP, OSPF, BGP

Question 7

Define the term Routing

Answer 7

Routing refers to taking a packet from one device & sending it through the network to another device on a different network.

Question 8

What are the minimum factors a router must know to route packets?

Answer 8

Destination address
Neighbor routers
Possible routes
Best route
How to maintain & verify routing information

Question 9

What are the only concerns of a router?

Answer 9

Possible destination networks and the best path to each network. They don’t care about hosts

Question 10

What are the fundamental functions of a router?

Answer 10

Best Path Selections and forwarding packets to destination

Question 11

What are the two types of Dynamic routing?

Answer 11

Interior Gateway Protocol (IGP) and Exterior Gateway Protocol (EGP)

Question 12

What are the 2 types of IGP’s?

Answer 12

Distance Vector Protocols (DVPs)

Link State Protocols (LSPs)

Question 13

Name the three DVP Protocols

Answer 13

Routing Information Protocol (RIPv1/2)
Interior Gateway Routing Protocol (IGRP)
Enhanced Interior Gateway Routing Protocol (EIGRP)

Question 14

Name the two LSP Protocols

Answer 14

Open Shortest Path First (OSPF)

Intermediate System-to-Intermediate System (IS-IS)

Question 15

What is the difference between Static & Dynamic Routing

Answer 15

In static routing, next hop routes are manually configured in the routers. In dynamic routing, routers share information to learn the route to a certain destination

Question 16

What Protocols are used in Dynamic Routing?

Answer 16

Routing Information Protocol (RIP)
Open Shortest Path First (OSPF)
Enhanced Interior Gateway Routing Protocol (EIGRP)
Border Gateway Protocol (BGP)

Question 17

What is the basic procedure that all Routing Protocol Algorithms follow?

Answer 17

1. Send & receive updates
2. Calculate best path; install routes
3. Detect & react to topology changes

Question 18

List the criteria used to compare routing protocols

Answer 18

Time to Convergence
Scalability
Resource Usage
Implementation & Maintenance

Question 19

List the two key concepts for Routing

Answer 19

Metric and Convergence

Question 20

What is a Metric?

Answer 20

A value used to define the suitability of a particular route. Used by routers to determine which routes are better than others

Question 21

What is Convergence?

Answer 21

A state where all routers on the internetwork share a common view of the internetwork routes

Question 22

List the types of routing metrics used by routing protocols

Answer 22

Hop Count
Bandwidth
Delay
Load
Reliability
Cost

Question 23

What is an Autonomous System?

Answer 23

A system that uses IGPs as routing protocols; A group of routers under the control of a single administration

Question 24

Where are IGP’s used?

Answer 24

Inside of an Autonomous System (AS)

Question 25

Where are EGP’s used?

Answer 25

Between multiple Autonomous Systems (AS)

Question 26

What is a Stub Network?

Answer 26

Networks with one route to the internet

Question 27

What is a Stub Router?

Answer 27

Routers with only one route out

Usually the last in a chain of routers

Question 28

What are the three Routing Principles?

Answer 28

1. Every router makes its decision alone, based on the information it has in its own routing table
2. The fact that one router has certain information in its routing table does not mean that other routers have the same information
3. Routing information about a path from one network to another does not provide routing information about the reverse, or return path

Question 29

What is a Default Static Route?

Answer 29

A route that will match all packets

Question 30

What is Route Summarization?

Answer 30

The process of combining a number of static routes into a single static route

Question 31

What is the benefit of summarizing a route?

Answer 31

Reduces the size of the routing table

Question 32

What are the steps in configuring a summary route?

Answer 32

1. Delete the current static route
2. Configure the summary static route
3. Verify the new static route

Question 33

What is the Cisco IOS command to configure Static Routes?

Answer 33

ip route {network-address} {subnet-mask} {interface}

Question 34

Can existing static routes set via ip route be modified?

Answer 34

No, the old static route must be deleted

Question 35

What is the Cisco IOS command to delete a Static Route?

Answer 35

no ip route {network-address} {subnet-mask} {interface}

Question 36

How is a Default Static Route configured via Cisco IOS commands?

Answer 36

Similar to configuring a static route, except that the Destination IP and Subnet Mask are all 0’s

e.g. ip route 0.0.0.0 0.0.0.0 {interface}