DNS

Question 1

What are the three components of DNS?

Answer 1

Clients
Recursive Servers
Authoritative Servers

Question 2

What is a resource record?

Answer 2

Maps a name to some data, and has some bookkeeping data on them.

Question 3

What does an A record contain?

Answer 3

A IPv4 address

Question 4

What does an AAAA record contain?

Answer 4

A IPv6 address

Question 5

How are domain name questions resolved?

Answer 5

Clients ask recursive servers. Recursive servers start at the root, and iterate downwards asking for the nameserver of the next label down, until they can finally ask the last nameserver for the required resource record.

Question 5

How does DNS caching work?

Answer 5

At each stage, everyone caches the data they get. Each record they receive has a time to live, once this expires they discard the record.

Question 6

What is an authoritative server?

Answer 6

For a given domain, there will be one or more nameservers specified in some zone.
Each of these specified nameservers is authoritative for the specified domain.

Question 7

What is an RR set?

Answer 7

The set of all Resource Records of a given record type for a given name

Question 8

What are DNS clients also known as?

Answer 8

Resolvers

Question 9

What are authoritative servers also known as?

Answer 9

Iterative servers

Question 10

What are recusive servers also known as?

Answer 10

Caching servers