Chapter 17 - Learning IPv4 Routes with OSPF v2

Question 1

Examples of this include RIP, EIGRP, OSPF, and BFP.

Answer 1

Routing protocol

Question 2

Both of these terms refer to a protocol that defines a packet structure and logical addressing. Examples include IP Version 4 and IP Version 6.

Answer 2

Routed protocol and routable protocol.

Question 3

What are 4 main routing protocol functions?

Answer 3

1) Learn routing information about IP subnets from other neighbor routers.
2) Advertise routing information about IP subnets to other neighbor routers.
3) Pick the best route based on metric, if more than one possible route exists to reach a subnet.
4) Convergence - If the network topology changes, react by advertising that some routes have failed and pick a new currently best route.

Question 4

What are 2 major categories of routing protocols?

Answer 4

Interior gateway protocols and Exterior gateway protocols

IGP and EGP

Question 5

What is a routing protocol that was designed and intended for use inside a single autonomous system (AS)?

Answer 5

IGP

Question 6

What is a routing protocol that was designed and intended for use between different autonomous systems?

Answer 6

EGP

Question 7

This term refers to the logic and processes used by different routing protocols to solve the problem of learning all routes, choosing the best route to each subnet, and converging in reaction to changes in the internetwork.

Answer 7

Routing Protocol Algorithm

Question 8

What are the 3 main branches of routing protocol algorithms that exist for IGP routing protocols?

Answer 8

1) Distance vector
2) Advanced distance vector
3) Link-state

Question 9

What was the first popularly used IP distance vector protocol?

Answer 9

Routing Information Protocol or RIP

Question 10

What IGP metric does RIP-2 use?

Answer 10

Hop Count

Question 11

What IGP metric does OSPF use?

Answer 11

Cost - This is the sum of all interface cost settings for all links in a route, with the cost defaulting to be based on interface bandwidth.

Question 12

What IGP metric is used by EIGRP?

Answer 12

Composite of bandwidth and delay - Calculated based on the route’s slowest link and the cumulative delay associated with each interface in the route.

Question 13

What is the concept an IOS uses when it must choose between routes learned using different routing protocols?

Answer 13

Administrative Distance

Question 14

What is the default admin distance for a connected route type?

Answer 14

0

Question 15

What is the default admin distance for a static route?

Answer 15

1

Question 16

What is the default admin distance for BGP (external routes)?

Answer 16

20

Question 17

What is the default admin distance for EIGRP (internal routes)?

Answer 17

90

Question 18

What is the default admin distance for IGRP?

Answer 18

100

Question 19

What is the default admin distance for OSPF?

Answer 19

110

Question 20

What is the default admin distance for IS-IS?

Answer 20

115

Question 21

What is the default admin distance for RIP?

Answer 21

120

Question 22

What is the default admin distance for EIGRP (external routes)?

Answer 22

170

Question 23

What is the default admin distance for BGP (internal routes)?

Answer 23

200

Question 24

To find its router ID or RID, what 3-step process does the router use when the router reloads and brings up the OSPF process?

Answer 24

1) If the router-id rid OSPF subcommand is configured, this value is used as the RID.
2) If any loopback interfaces have an IP configured, and the interface status is up, the router picks the highest numeric IP address among these loopback interfaces.
3) The router picks the highest numeric IP from all other interfaces whose interface status code (first status code) is up.

Question 25

A network engineer can configure an interface as an OSPF passive interface, telling the router to do (or not do) what 3 things?

Answer 25

1) Quit sending OSPF Hellos on the interface
2) Ignore received Hellos on the interface
3) Do not form neighbor relationships over the interface

Question 26

What is the difference between OSPF v2 and OSPF v3?

Answer 26

OSPF v2 is used with IPv4 while OSPF v3 is used with IPv6.