Routing

Question 1

or 0.0.0.0, a designation for a gateway in a routing table, representing a network ID that is directly connected to the router (no gateway needed)

Answer 1

On-link

Question 2

a relative value in a routing table which determines the cost of using that route - the router will send a packet down a route with the lowest cost

Answer 2

metric

Question 3

a feature in many networks where the internal IP addresses are hidden on the LAN but are still able to communicate on the Internet - this is used to protect computers and conserve IP addresses

Answer 3

network address translation (NAT)

Question 4

the most common form of NAT, where a router records the source and destination IP addresses as well as the port number, then swaps the source IP address with that of the external IP address and the port number with another port number; those numbers are then compared when a packet is received

Answer 4

port address translation (PAT)

Question 5

a form of NAT where a single machine, such as a Web server, is given a static address that is not private, allowing one outside of the network to access the device

Answer 5

Static NAT (SNAT)

Question 6

a form of NAT where a specific local address is designated for various services, and outside sources can request a service from it; however, the port for that service is hidden, and instead a router translates the incoming port number into a recorded ip address and other port number; the service is mapped to a specific IP address and port number

Answer 6

port forwarding

Question 7

a form of NAT in which a number of computers share a pool of routable IP addresses even numbering less than the total number of computers - the NAT doles out IP addresses at the request of a computer needing to access the Internet

Answer 7

dynamic NAT (DNAT), also pooled NAT

Question 8

switching metric (for comptia, also routing metric) that determines the largest frame that technology can handle

Answer 8

maximum transmission unit (MTU)

Question 9

routing protocol that calculates the total cost of each routes and chooses the one with the lowest cost

Answer 9

distance vector routing protocol

Question 10

the first distance vector routing protocol, which had a max hop count of 15, had issues with network overloads from updates, did not use VLSM, and had no authentication

Answer 10

routing information protocol version 1 (RIPv1)

Question 11

a current distance vector routing protocol which has authentication and VLSM, but still has a number of problems, like having a large time to convergence for large WANs

Answer 11

routing information protocol version 2 (RIPv2)

Question 12

one or more networks governed by a single dynamic routing protocol

Answer 12

autonomous system (AS)

Question 13

numbers used by AS’s to communicate with each other rather than IP addresses, currently 32-bit with a dot between each 16-bit part

Answer 13

autonomous system number (ASN)

Question 14

generic name for a protocol used by AS’s to communicate with each other

Answer 14

exterior gateway protocol (EGP)

Question 15

the one protocol used for communicate between autonomous systems

Answer 15

border gateway protocol (BGP)

Question 16

generic name for a protocol used by networks within an AS to communicate

Answer 16

interior gateway protocol (IGP)

Question 17

name given to AS-to-AS routers

Answer 17

edge router

Question 18

a simplication of routing tables to managable levels by only keeping track of routers connections to subsets of locations

Answer 18

route aggregation

Question 19

a type of dynamic routing protocol where routers only forward individual route changes rather than the whole routing table at regular intervals

Answer 19

link state

Question 20

the commonly-used IGP in the world, it establishes relationships with neighboring routers using “Hello” packets, exchange info via LSA packets, then decide their own optimal routes, reaching convergence quickly; the metric of this protocol is cost, and they use LSA’s to recompute new routes in the event of a route going down

Answer 20

Open Shortest Path First (OSPF)

Question 21

packets sent from router to router in an OSPF area, these contain information on routers and networks

Answer 21

link state advertisement

Question 22

a link state dynamic routing protocol that works with IPv6 addresses and is the de facto standard for ISPs

Answer 22

Intermediate System to Intermediate System (IS-IS)

Question 23

proprietary protocol of Cisco that is not entirely distance vector or link state; it contains aspects of both, and is called by Cisco an advanced distance vector protocol (might be called this on exam)

Answer 23

Enhanced Interior Gateway Routing Protocol (EIGRP)

Question 24

ability of routers to use two different routing protocols separately, such as taking routes learned by one protocol and announcing them over another protocol

Answer 24

route redistribution

Question 25

the Cisco console (serial) cable used for connecting to their routers

Answer 25

roller (Yost) cable

Question 26

a program used to access and configure a managed device

Answer 26

terminal emulator

Question 27

advanced tools that describe, visualize, and configure the entire network, including routers, switches, and even computers

Answer 27

Network Management Software (NMS)