Section 9: Network Services

Question 1

DHCP

Answer 1

Dynamic Host Configuration Protocol
o Assigns devices with IP addresses and also provides them a subnet mask, default gateway, and DNS server
o Operates over ports 67 and 68 using UDP

Question 2

DNS

Answer 2

Domain Name System
o Converts domain names to IP addresses using a hierarchical and decentralized system of naming
o Operates over UDP (Domain Lookup) and TCP (Zone Transfers) using port 53

Question 3

NTP

Answer 3

Network Time Protocol
o Synchronizes clocks between systems communicating over a packet-switched (TCP/IP), variable-latency data network
o Sent over UDP using port 123

Question 4

DNS Zone Transfer

Answer 4

Sharing of information between DNS servers about which domain names they have and their associated IP addresses - Uses TCP Port 53

Question 5

IP Helper

Answer 5

Forwards several UDP broadcasts (If the DHCP client and server are on different network segments, the router on the client’s network segment must be configured with an IP helper address.)

Question 6

FQDN

Answer 6

Fully Qualified Domain Name (WWW.DomainName.com)
This is when a domain name is under a top-level provider
● The most common top-level provider:
o .com
o .mil
o .edu
o .org
o .net

Question 7

URL

Answer 7

Uniform Resource Locator
(https:// FQDN = https://www.DomainName.com,…)

Question 8

*DNS A Record

Answer 8

▪ Address Record
▪ Used to link a hostname to an IPv4 address
▪ A-records work for IPv4 addresses
▪ AAAA records work for IPv6 addresses

Question 9

*DNS CNAME Record

Answer 9

Canonical Name Record
▪ Used instead of a A record or AAAA record if you want to point a domain to another domain name or subdomain

Question 10

*DNS MX record

Answer 10

Mail Exchange Record
▪ Used to direct emails to a mail server
▪ Used to indicate how email messages should be routed using the Simple Mail Transfer Protocol, or SMTP, over port 25
▪ Can only be used to point to another domain, not an IP address

Question 11

DNS SOA Record

Answer 11

Start of Authority Record
▪ Used to store important information about a domain or zone

Question 12

DNS Zone Transfer

Answer 12

The process of sending DNS records data from the primary nameserver to a secondary name server
▪ Uses the TCP protocol to transfer the data to ensure data is successfully sent by the primary server and received by the second server

Question 13

*DNS PTR Record

Answer 13

Pointer Records
▪ Used to correlate an IP address with a domain name
▪ The opposite of an A record
▪ Always stored under the .arpa (top-level domain)
(Reverse Lookup - IP address to domain name)

Question 14

*DNS AAAA Record

Answer 14

Links a hostname to an IPv6 address

Question 15

*DNS TXT Record

Answer 15

Text records
▪ Used by domain administrators to add text into the domain name system (DNS)
▪ A place to store machine-readable data

Question 16

DNS SRV Record

Answer 16

Service Record
▪ Used to specify a host and port for a specific service
▪ Can specify a port along with our IP address

Question 17

DNS NS Record

Answer 17

Name Server Record
▪ Used to indicate which DNS name server is the authoritative one for a domain