IP Protocol

Internet Protocol

[ basics ]

Every computer connected to the Internet has a unique IP address that allows it to be “found” and receive data.

The network protocol IP is responsible for addressing and routing data between computers on a network.

ping 192.168.0.1▋

Domain Name and IP

We’re used to visiting websites through addresses like tester-today.com, but behind those names are IP addresses.

It’s easier for us to remember domain names, and easier for computers to work with numbers.

How DNS Works — The Domain Name System

1 You enter an address in the browser example.com

2 The computer sends a request to the DNS server

3 The DNS server finds example.com and returns IP 93.184.216.34

DNS works like a phone book: it finds the number by name

Main Functions of IP

Addressing

Each device receives a unique IP address, for example,192.168.0.1, by which it can be identified on the network.

Routing

IP determines the path data takes to reach the recipient. Routers are used for this purpose.

Packet Switching

Data is divided into small packets, each of which is transmitted separately and may take a different route.

IP Protocol in Action

1 Your browser sends a request to the server example.com

2 The DNS server translates the domain name into an IP address

3 The request is split into packets and sent to the server

4 The server receives the packets, reassembles them, and sends a response, also using IP

5 The response travels back through the network and returns to you

Task

DNS is usually used to find the IP address by domain name. Now — the other way around! Try to figure out which domain name corresponds to the IP address 8.8.8.8

Enter the IP address 8.8.8.8 into the address bar and see where it takes you.

The process of converting an IP back into a domain name is called reverse DNS lookup.