Chapter 10

Question 1

is a collection of networks under a common administrative domain, which simply means that all routers sharing the same routing table. p299

Answer 1

autonomous system (AS)

Question 2

is an integer from 0 to 255, where 0 equals the most trusted route and 255 the least. A value of 255 essentially means, “No traffic is allowed to be passed via this route.”p300

Answer 2

administrative distance (AD)

Question 3

If both advertised routes to the same network have the same AD, then routing-protocol metrics like________or the amount of bandwidth of the lines will be used to find the best path to the remote network. p300

Answer 3

hop count

Question 4

But if both advertised routes have the same AD as well as the same metrics, then the routing protocol will________to the remote network. p300

Answer 4

load-balance

Question 5

What is the Distance vector. p302

Answer 5

The distance-vector protocols find the best path to a remote network by judging—you guessed it—distance. Each time a packet goes through a router, it equals something we call a hop. The route with fewest hops to the network is determined to be the best route.

Question 6

What is the Link state. p302

Answer 6

U sing link-state protocols, also called shortest-path-first protocols, the routers each create three separate tables. One of these tables keeps track of directly attached neighbors, one determines the topology of the entire internetwork, and one is used as the actual routing table.

Question 7

What is Hybrid. p303

Answer 7

A hybrid protocol uses aspects of both distance vector and link state, and at this writing, there’s only one—EIGRP. It happens to be a Cisco proprietary protocol, meaning that it will only run on Cisco equipment.

Question 8

because a router receiving an update from a neighbor router believes the information about remote networks without finding out for itself if it actually is correct. p303

Answer 8

routing by rumor

Question 9

If a router finds more than one link with the same hop count to the same remote network, it will automatically perform what’s known as. p303

Answer 9

round-robin load balancing

Question 10

RIP version 1 uses only ________ which means that all devices in the network must use the same subnet mask.p305

Answer 10

classful routing

Question 11

RIP version 2 provides something called________and does send subnet mask information with the route updates. p305

Answer 11

prefix routing

Question 12

once all the routers have converged, the routing table in each router keeps information about three important things: p305

Answer 12

The remote network number
The interface that the router will use to send packets to reach that particular network
The hop count, or metric, to the network

Question 13

(VLSMs) stand for. p306

Answer 13

Variable Length Subnet Masks (VLSMs)

Question 14

is classless, meaning that the routing protocol sends subnet-mask information with the route updates. The reason it’s good to do this is to save address space. p306

Answer 14

Variable Length Subnet Masks (VLSMs)

Question 15

what is a Neighbor table p311

Answer 15

Each router keeps state information about adjacent neighbors. When a newly discovered neighbor is learned about, the address and interface of that neighbor are recorded, and the information is held in the neighbor table and stored in RAM.

Question 16

what is a Topology table p311

Answer 16

T he topology table is populated by the neighbor table, and the best path to each remote network is found by running DUAL.

Question 17

is a path whose reported distance is less than the feasible (best) distance, and it is considered a backup route. p311

Answer 17

Feasible successor (backup routes)

Question 18

is the best route to a remote network. A successor route is used by EIGRP to forward traffic to a destination and is stored in the routing table.p311

Answer 18

Successor (routes in a routing table)

Question 19

The neighbor table is maintained through the use of___________ that are exchanged by all routers to determine which other routers are available to exchange routing data with. p313

Answer 19

hello packets

Question 20

(OSPF) stands for what. p314

Answer 20

Open Shortest Path First (OSPF)

Question 21

is an open standard routing protocol that’s been implemented by a wide variety of network vendors. p314

Answer 21

Open Shortest Path First (OSPF)

Question 22

OSPF provides the following features: p314

Answer 22

Consists of areas and autonomous systems
Minimizes routing update traffic
Allows scalability
Supports VLSM/CIDR
Has unlimited hop count
Allows multi-vendor deployment (open standard)
Uses a loopback (logical) interface to keep the network stable

Question 23

The following are reasons you really want to create OSPF in a hierarchical design: p315

Answer 23

To decrease routing overhead
To speed up convergence
To confine network instability to single areas of the network

Question 24

The router that connects these ASs is called an . p316

Answer 24

Autonomous System Border Router (ASBR).

Question 25

is an IGP, meaning that it’s intended for use within an administrative domain or network, not for routing between ASs. That would be a job that an EGP, such as BGP, which we just covered, would handle instead. p316

Answer 25

Intermediate System to Intermediate System (IS-IS)