Question

Identify the correct sequence in which the following packets are transmitted on the network by a host when a browser requests a webpage from a remote server, assuming that the host has just been restarted. 
1. HTTP GET request, DNS query, TCP SYN
2. DNS query, HTTP GET request, TCP SYN
3. DNS query, TCP SYN, HTTP GET request
4. TCP SYN, DNS query, HTTP GET request

Answer 1

Correct Answer - Option 3 : DNS query, TCP SYN, HTTP GET request

During packet transmission, first step is to make the DNS query.

Whenever client makes a query, server identify the DNS. DNS (domain name server) query is used to identify the address of DNS.

After this, a TCP connection is to be established for further communication. TCP connection will be established by sending TCP SYN message.

After connection establishment, HTTP GET request to the server to retrieve the webpage it should display. After the server has sent the response, it closes the TCP connection.