10 - DNS and Email

Question 1

Old solution for tracking IPs

Answer 1

hosts.txt

Question 2

DNS

Answer 2

DOmain Name SYstem

Question 3

Domain Name limitations

Answer 3

(almost) unlimited

Question 4

Recursive Query

Answer 4

Server asks other servers for ip address directly

Question 5

Iterative Query

Answer 5

Server responds with another server to contact

Question 6

MAx domain name length

Answer 6

255 total
63 in each part

Question 7

What is RR?

DNS Record type

Answer 7

Resource Record

Question 8

A record

Answer 8

host to ip

Question 9

NS record

Answer 9

domain to ip of authoritative name server

Question 10

CNAME record

Answer 10

alias to canonical name

Question 11

MX Record

Answer 11

Mailserver name

Question 12

What result types do you get from a DNS query?

Answer 12

Positive - one or more RR match
Negative - definitely no RR match
Server Fail - cannot find answer
Refused - not allowed to query

Question 13

DNS port

Answer 13

53

Question 14

DNS server roles

Answer 14

Resolver
Caching Nameserver
Authoritative Nameserver

Question 15

DNS Resolver

Answer 15

Takes request, formates into UDP packet and sends to cache

Question 16

DNS Caching nameserver

Answer 16

Returns answer if known. Or forwards

Question 17

Email user agent

Answer 17

Reading,composing,editing etc

Question 18

Mail Servers components

Answer 18

mailbox
message queue
SMTP protocol (TCP!)