Internet Protocol⌗

The Internet Protocol (IP) is the protocol by which data is sent across the Internet.

What is an IP address?⌗

An IP address is a unique string of numbers assigned to every device connected to the Internet.

Types of IP addresses⌗

Dynamic IP⌗

Dynamic IP addresses are temporary addresses that change from time to time.

They are assigned to devices on a network by the Dynamic Host Configuration Protocol (DHCP).

Static IP⌗

Static IP addresses are permanent addresses that do not change until the device is decommissioned.

Public IP⌗

Public (or) external IP addresses can be accessed directly over the Internet and are used for external communications.

Public IP addresses are assigned to a router or network by the Internet Service Provider (ISP).

Private IP⌗

Private (or) internal (or) local IP addresses are assigned to all devices connected to a network. They are the same for any network.

Ranges:

  • Class A: 10.0.0.0 to 10.255.255.255
  • Class B: 172.16.0.0 to 172.31.255.255
  • Class C: 192.168.0.0 to 192.168.255.255

Note: These are IPv4 addresses (more on that later)

Shared IP⌗

A shared IP address is used by multiple domains or websites.

Dedicated IP⌗

A dedicated IP address is an address allotted exclusively to one website.

Loopback IP⌗

Data sent to a loopback address are looped and sent back to the device.

They are managed entirely within the operating system (the data never reaches the network).

Range: 127.0.0.0 to 127.255.255.255 (IPv4)

The most common loopback address is localhost (IPv4: 127.0.0.1, IPv6: ::1).

Versions of IP⌗

Currently, there are two version of IP publicly used - IPv4 and IPv6.

IPv4⌗

Internet Protocol version 4 (IPv4) is the first public version of the IP.

IPv4 is a 32-bit address. It has 4 octets.

IPv4 format

In November 2019, we ran out of unallocated IPv4 addresses. However, IPv4 addresses continue to be in use and will most likely coexist with IPv6 for many years.

IPv6⌗

Internet Protocol version 6 (IPv6) is the second public version of the IP, intended to become a successor to IPv4.

IPv6 is a 128-bit address. It has 16 octets. Each octet ranges from 0000 to FFFF (hexadecimal values).