DNS Record Types& Subnet Formulas

Question 1

A

Answer 1

Maps hostname to IPv4

Question 2

AAAA

Answer 2

Maps hostname to IPv6

Question 3

CNAME

Answer 3

Canonical name. Ex(diontraining.com = www.diontraining.com)

Question 4

MX

Answer 4

Mail exchange record maps domain name to email server

Question 5

NS

Answer 5

Denotes authoritative name server for the domain

Question 6

PTR

Answer 6

Pointer record refers to canonical name; used for reverse (give IP get FQDN back) DNS lookups

Question 7

SOA

Answer 7

Start of Authority. Provides contact info, primary name server, refresh times

Question 8

SRV

Answer 8

Generalized service location record. Locates where other services are on the DNS

Question 9

TXT

Answer 9

designed to hold humanm readable code.

Question 10

SPF protocol

Answer 10

Sender Policy Framework
prevents mail spoofing
mail servers check thaT incoming mail really did come from an authorized host

Question 11

DKIM

Answer 11

Domain Keys Identified Mail
Digitally sign your outgoing mail, validated by mail server not usually seen by the end user.

Question 12

ZONE TRANSFERS

Answer 12

used for redundancy in dns servers. full zone transfers can be a security risk.

Question 13

Number of Created Subnets

Answer 13

2^s, s is number of borrowed bits

Question 14

Number of Assignable IP Addresses

Answer 14

2^h-2
h is number of host bits or 0s in binary