5.2-DNS

Question 1

To map human readable names like www.mcewenmedia.com to IP Addresses

Answer 1

DNS - Domain Name System

Question 2

Local DNS resolver

Answer 2

typically configured automatically using Using DHCP (Domain Host configuration protocol)

Question 3

TTL

Answer 3

Indicates how long local DNS resolver can cache domain names.

Question 4

Most common type of DNS record

Answer 4

A-Record which maps an IP Address to a domain name

Question 5

Maps a domain name to an authoritative nameserver for that domain (referred to as a “referrals”)

Answer 5

Name Server Record or NS

Question 6

Mail server for a particular domain

Answer 6

MX record

Question 7

Alias or Canonical name (pointer from alias to another domain name)

Answer 7

CNAME

Question 8

Maps IP addresses to a domain name (reverse lookup)

Answer 8

PTR

Question 9

Maps a domain name to an IPv6 address

Answer 9

AAAA (uad A)

Question 10

You can see a question and an answer section.

shows info like: ttl, record type, IP Address

Answer 10

dig

Question 11

dig ns gatech.edu

Answer 11

shows A and AAAA

Question 12

dig mx gatech.edu

Answer 12

Returns the mail server, ttl, priority levels

Question 13

dig +trace gatech.edu

Answer 13

The full lookup hierarchy to see every step of the DNS lookup process

Question 14

Lookup IP address 130.207.97.11

What is corresponding in-addr.arpa domain name?

Answer 14

11.97.207.130.in-addr.arpa

The reversal of the octets in this name corresponds to a strict traversal of the hierarchy from the highest levels of the hierarchy at in-addr.arpa to the lower levels as the IP address moves from higher to lower parts of the hierarchy