Computer Science · Ch 10 — Computer Networks
IP Address
IP Address
An IP address (Internet Protocol address) is a unique identifier assigned to each node in a network that uses the Internet Protocol for communication. Its purpose is the same as a MAC address — to uniquely identify a device on a network — but with a crucial difference: an IP address can change. If you move a computer from one network to another, its IP address will typically change. A MAC address, by contrast, is permanently burned into the hardware.
Because an IP address identifies a device on the global Internet, knowing a computer's IP address lets you communicate with that computer from anywhere in the world.
IPv4 (Internet Protocol version 4)
The original IP addressing scheme is called IPv4. An IPv4 address is a 32-bit numeric address. It is written as four numbers separated by periods, where each number is the decimal (base-10) representation of an 8-bit binary number. This means each of the four numbers can range from 0 to 255.
A sample IPv4 address looks like: 192.168.0.178
A 32-bit address offers just under 4.3 billion unique addresses. With the explosion of internet-connected devices (phones, laptops, smart appliances, etc.), this pool was recognised as insufficient.
IPv6 (Internet Protocol version 6)
To solve the address shortage, a new version called IPv6 was proposed. An IPv6 address is 128 bits long — a massive increase that provides an astronomically larger number of unique addresses.
An IPv6 address is represented by eight groups of hexadecimal (base-16) numbers separated by colons.
A sample IPv6 address looks like: 2001:CDBA:0000:0000:0000:0000:3257:9652
- IPv4: 32 bits, decimal notation, four numbers separated by dots (e.g.,
192.168.0.178). - IPv6: 128 bits, hexadecimal notation, eight groups separated by colons (e.g.,
2001:CDBA:0000:0000:0000:0000:3257:9652). …