Core Concepts (Module 2)

Question 1

Used to resolve an IP address into a MAC address?

A. ARP
B. Gratuitous ARP
C. RARP
D. DNS

Answer 1

C (ARP)

Explanation: ARP (Address Resolution Protocol) is the protocol that is used to discover the mac
address of a host if the ip address is known.

Question 2

Host1 MAC = AAAA.AAAA.AAAA
Host2 MAC = BBBB.BBBB.BBBB
Host 3 MAC = CCCC.CCCC.CCCC

Host 1 wants to send data to Host 2, but does not have Host 2’s mac address in its ARP table.
What would be the destination address for an ARP packet sent in the following scenario?

A. BBBB.BBBB.BBBB

B. BBBB.BBBB.BBBB & CCCC.CCCC.CCCC

C. FFFF.FFFF.FFFF

D. 0000.0000.0000

Answer 2

C (FFFF.FFFF.FFFF)

Explanation: When the mac address of the destination is not known, the host will broadcast an ARP
onto the network trying to find the host with the identified IP address. The destination address of a
broadcast onto a local LAN is FFFF.FFFF.FFFF.

Question 3

Briefly describe the function of DNS?

Answer 3

Explanation: DNS, or Domain Name Service is a service that translates the url you type into your web
browser into a destination IP address. It would be virtually impossible to remember all the IP addresses
for the websites each of us visit. It would also be extremely annoying to have to pull out a “phone book”
of sorts that contains the IP addresses and urls of entities on the Internet and manually look up the IP
address to enter into your web browser. Instead, DNS servers take care of this automatically by

Question 4

Where can a DNS server be located?

A. only on the local network
B. on the local network or the Internet
C. only on the Internet
D. none of the above

Answer 4

B (on the local network or the Internet)

Explanation: DNS servers can be managed and hosted internally by a network administrator. There
are also public DNS servers on the Internet that are maintained by other entities. One of Google’s DNS
servers = 8.8.8.8.

Question 5

There is a monthly or annual cost for subscribing to a public DNS such as Google DNS?

A. TRUE
B. FALSE

Answer 5

B (FALSE)

Explanation: There is no cost or subscription required to use public DNS servers, such as Google’s DNS.