day 4

Question 1

route summarization

Answer 1

the ability to take a group of subnetworks and summarize them, as one routing statement entry

Question 2

reverse route summarization

Answer 2

the ability to take a summarized route and determine what networks a summary covers

Question 3

default route

Answer 3

gives the router a path to send traffic to destinations that are not in the routing table.

Question 4

gateway of last resort

Answer 4

the next hop specified in a default route is reffered to as the gateway of last resort.

that next hop will usually be the path out of the internet.

Question 5

dynamic routing protocols

Answer 5

build routing tables from information received from other routers in the network.

Question 6

autonomous system (AS)

Answer 6

a group of networks under mutual network administration and sharing a common routing methodology

Question 7

interior gateway protocol (IGP)

Answer 7

used within an AS to maintain a map for the local topology and adjacant areas

Question 8

three types of IGP’s

Answer 8

distance-vector, link-state, or hybrid

Question 9

Exterior Gateway Protocol (EGP)

Answer 9

each AS exchanges reachability information with other ASs using an EGP

Question 10

Border Gateway Protocol (BGP)

Answer 10

most common exterior gateway protocol

Question 11

distance-vector routing protocols

Answer 11

advertised as vectors of distance and direction.

the distance metric is usually router hop.

Question 12

distance vector routing protocols

Answer 12

call for each router to send all or some portion of its routing table only to its neighbors.

EVERYTHING ONLY TO ITS NEIGHBOR

Question 13

link state routing protocols

Answer 13

routers originate information about themselves, their connected links, and the state of those links.
link state routers only send the state of their routers to other routers

Question 14

link state routing protocols

Answer 14

link state protocols send only the state of their own links to all routers.
link state algorithms send small updates everywhere.
SMALL UPDATES SENT EVERWHERE

Question 15

link state routing protocols

Answer 15

OSPF, IS-IS, NLSP

Question 16

administrative distance

Answer 16

the lower the administrative distance, the more preferred that route will be

Question 17

administrative distances

Answer 17

connected interface        0
static route                      1
external BGP route          20
Internal EIGRP route        90
OSPF route                     110
RIP route                        120

Question 18

Routing information protocol version 2 (RIPv2)

Answer 18

distance vector routing protocol that uses hop count as a metric
maximum hop count is 15; 16 is unreachable.
updates RIP to allow VLSM and authentication.
RIP v2 updates are destined for the multicast address 224.0.0.9 using UDP port 520

Question 19

RIP timers

Answer 19

Route update timer, route invalid timer, route flush timer, hold-down timer

Question 20

route update timer

Answer 20

sends complete routing table updates to neighbors every 30 seconds

Question 21

route invalid timer

Answer 21

if router has not heard any updates within the invalid timer period, the route is deemed invalid.
the router will send an update to its neighbors, letting them know the route is invalid

Question 22

route flush timer

Answer 22

amount of time for a router to remove an invalid route from the routing table

Question 23

hold-down timer

Answer 23

when changes occur on a route, the route is placed in hold down..no changes are accepted until the hold down timer expires

Question 24

loop avoidance

Answer 24

Triggered updates, split horizon, route poisoning

Question 25

triggered updates

Answer 25

triggered updates are sent before the update timer has expired

Question 26

split horizon

Answer 26

routes that are learned from a neighboring router are not sent back to that neighboring router

Question 27

route poisoning

Answer 27

route poisining is a method by which RIP shuts down redundant links

Question 28

show ip route

Answer 28

this command displays the routing table as it currently exists on the router

Question 29

show ip protocols

Answer 29

identifies other running protocols which are not currently involved in the IP routing process