1.6 Network Services

Question 1

Explain the DNS domain hierarchy from top to bottom.

Answer 1

1. Root Domain- “.” (period always appears at the end of every domain address)
   eg. “www.google.com.”
2. Top Level Domains- “com, net, org”
3. Second level domains- “google”
4. Third Level domains- “www, mail, docs”

Question 2

What is the State of Authority (SOA) DNS record?

Answer 2

Indicates that the server is the best authoritative source for data concerning the zone.
Each zone must have an SOA record, and only one SOA record can be in a zone.
Determines caching duration(before requesting a new one)/usually 50% TTL (Time To Live)

Question 3

What is the Name Server (NS) DNS record?

Answer 3

Identifies a DNS server functioning as an authority for the zone, Each DNS server in the zone (whether primary master or secondary) must be represented by an NS record

Question 4

What is the Address (A) DNS record?

Answer 4

Providers a name –to-address mapping that supplies an IPv4 address for a specific DNS name.

Question 5

What is the Quad Address (AAAA) DNS record?

Answer 5

Provides a name –to-address mapping that supplies an IPv6 address for a specific DNS name.