An Overview of DNS

Question 1

An Overview of DNS

Answer 1

• Translates human-readable names into computer-
readable IP addresses
• You only need to remember
www.ProfessorMesser.com

• Hierarchical
• Follow the path

Question 2

Distributed Databases

Answer 2

• Many DNS servers
• 13 root server clusters
• Hundreds of generic top-level domains (gTLDs) -
.com, .org, .net, etc.
• Over 275 country code top-level domains (ccTLDs) -
.us, .ca, .uk, etc.

Question 3

The DNS Resolution Process

Answer 3

1 - Request sent to local name server
2 - Name server queries root server
3 - Root response sent to local name server
4 - Name server queries .com name server
5 - .com Response sent to local name server
6 - Name server queries specific domain server
7 - Domain server responds to name server
8 - Name server provides result to local device
9 - Answer is cached locally

Question 4

Internal vs. External DNS

Answer 4

Internal vs. External DNS
• Internal DNS - Managed on internal servers
• Configured and maintained by the local team
• Contains DNS information about internal devices
• DNS service on Windows Server

• External DNS - Managed by a third-party
  
  • Does not have internal device information
  • Google DNS, Quad9

Question 5

Third-party DNS

Answer 5

• Managing DNS can be challenging
  
  • Especially in large environments
• Outsource the DNS
  
  • Cloud-based DNS services

• Features not available on a privately-hosted DNS
server
• High-availability, low latency, and scaling options