Network Addressing

Question 1

Subnet mask

Answer 1

Distinguishes which part of the IP address identifies the network ID and which part identifies the host
Blocks out (masks) the network portion of the IP address
Any part containing 255 is the network ID
Any part that’s all 0s is host ID

Question 2

CIDR

Answer 2

Classless inter-domain routing
Techs refer to subnet mask by the number of 1s it contains
Written as /(number of 1s)
Ex. /24 for 11111111.11111111.11111111.00000000 (255.255.255.0)

Question 3

DNS

Answer 3

Domain name system

Question 4

DNS Server

Answer 4

Keeps database that associate IP addresses with names

Question 5

DKIM

Answer 5

DomainKeys Identified Mail
Enable receiving servers to verify the messages they receive were signed by the sending server and have not been altered by intermediate servers

Question 6

SPF

Answer 6

Sender Policy Framework
List the IP and DNS addresses allowed to send e-mail for a domain
Enables receiving servers to discard/flag messages by illegitimate servers

Question 7

DMARC

Answer 7

Domain-based Message Authentication, Reporting, and Conformance records
Enables domain owners to indicate what receiving servers should do with e-mail that fails the DKIM or SPF checks
Enables domain owners to receive reports from large e-mail providers about the origin of the mail they received from the domain.

Question 8

DHCP

Answer 8

Dynamic Host Control Protocol
Obtains IP addresses automatically

Question 9

TCP

Answer 9

Transmission Control Protocol
Connection oriented
(HTTPS & SSH are considered connection oriented)

Question 10

UDP

Answer 10

User Datagram Protocol
Connectionless
(DHCP & TFTP are also connectionless)

Question 11

TCP/IP tools

Answer 11

ping (can you talk to another system)
ipconfig/ifconfig/ip (quick glance at network settings)
nslookup/dig (determine exactly what information the DNS server is giving you about a specific host)
tracert/traceroute (shows route a packet takes to get to its destination)

Question 12

APIPA

Answer 12

Automatic Private IP Addressing
Automatically assigns an IP address to the system when client cannot obtain an IP address automatically
Range between 169.254.0.1 through 169.254.255.254 set aside by IANA
Can only communicate with other computers on the same subnet

Question 13

IANA

Answer 13

Internet Assigned Numbers Authority