DNS And HTTP/s

Question 1

DNS (Domain Name System)

Answer 1

Infrastructure service translates human readable domain names into IP addresses for routers to understand

Question 2

DNS Steps

Answer 2

1. Client sends DNS query to recursive resolver
2. Resolver queries root and servers
3. IP address and cache are stored for future use

Question 3

HTTP

Answer 3

1. Browser sends requests
2. Server requests and sends responses
   Request line: GET/index.html
   Headers: metadata
   Status: (200 OK, 404 not found…)

Question 4

HTTPS

Answer 4

Encrypts HTTP for SSL/TLS to prevent data breaches. Uses SSL certificates for authentication.

Question 5

HTTP vs HTTPS

Answer 5

HTTP port is 80, HTTPS is 443.
HTTP is not secure but HTTPS is encrypted with SSL/TLS.

Question 6

HTTPS request steps

Answer 6

1. Browser requests IP address from DNS server
2. TCP does 3 way handshake (SYN -> SYN-ACK -> ACK)
3. HTTPS is used, data is encrypted
4. HTTP requests information (line, header, resources)
5. Server processes request and returns a status line
6. Browser renders content, TCP is closed with FIN-ACK