How the Web Works?

Question 1

What happens when you make a DNS request

Answer 1

1. The PC checks its local cache.
2. If it doesn’t exist, a request to your Recursive DNS Server will be made.
3. Recursive DNS also has a local cache of recently looked up domain names, If a result is found locally, this is sent back to The PC.(like Google, Facebook,..).
4. If not we search then in the internet’s root DNS servers.
5. The root servers ‘ job is to redirect you to the correct Top Level Domain Server, depending on your request.
6. The TLD server holds records for where to find the authoritative server to answer the DNS request.
7. Depending on the record type,** the DNS record is then sent back to the Recursive DNS Server by the Authoritive server, where a local copy will be cached for future requests** and then relayed back to the original client that made the request.

Question 2

Why the computer checks the Local Cache when making a request to a website?

Answer 2

your computer first checks its local cache to see if you’ve previously looked up the address recently

Question 3

Recursive DNS is provided by whom?

Answer 3

• A Recursive DNS Server is usually provided by your ISP, but you can also choose your own. This server also has a local cache of recently looked up domain names.
• it is usually when the requests made for heavily services such as Google, Facebook, Twitter stop.

Question 4

What is the Job of Root Servers in DNS process?

Answer 4

The root servers act as the** DNS backbone** of the internet; their job is to redirect you to the correct Top Level Domain Server, depending on your request.

For example, if you request www.tryhackme.com, the root server will recognise the Top Level Domain of .com and refer you to the correct TLD server that deals with .com addresses.

Question 5

What is the Role of TLD Server?

Answer 5

• The TLD server** holds records for where to find the authoritative server** to answer the DNS request.
• The authoritative server is often also known as the nameserver for the domain.

Question 6

What is the Authoritative server in DNS process?

Answer 6

An authoritative DNS server is the server that** is responsible for storing the DNS records for a particular domain name** and where any updates to your domain name DNS records would be made.

Question 7

what is the value with which a DNS record comes?

Answer 7

• DNS records all come with a TTL (Time To Live) value.
• This value is a number represented in seconds that the response should be saved for locally until you have to look it up again.

Question 8

What is the Purpose of Caching?

Answer 8

Caching saves on having to make a DNS request every time you communicate with a server.