IP, Subnet, and CIDR — Networking Days — 1

So many people know how to configure the IPs, CIDR or Subnets but most of these people don’t know what do they stand for. And as a DevOps or Sys, it’s really required to know these terms for the beginning.

IP

IP addresses are 32-bit long numbers, 4 octets, and each octet has 8 bits of data.

A single octet can represent all decimal numbers from 0 to 255.

Why 255?

As I said already, an octet can have 8 bit of data of maximum, and 2⁸ is equal to 256. So only 0–255 can be the numbers.

For example, 12.34.56.78 is a valid IP address. But 123.456.789.100 would not be, because it has numbers larger than could be represented by 8 bits.

IP Address or MAC Address

The first difference about the IP Address and Mac Address, that, IP Address are distributed in large sections to various organizations and companies, but MAC Addresses are determined by hardware vendors.

This means that IP addresses are more hierarchical, and easier to store data about than physical addresses are.

Think of IBM, which owns every single IP that has the number 9 as the first octet. At a very high level, this means that if an Internet router needs to figure out where to send a data…