CIDR — This isn’t the latest drink.
There are two main addressing schemes:
- Class A/B/C scheme
- CIDR (Classless Inter-Domain Routing)
The Class A/B/C schemes breaks the network and hosts at the decimal points of the notation (Conklin & White, 2021). Whereas, the Classless Inter-Domain Routing (CIDR) is notated by / and it refers to the number of significant bits that make up the routing or network portion.
So why are there two systems. It is fairly simple, CIDR makes it easier to annotate network diagrams and comprehend how a network is laid out.
Let’s take an example. The headmistress of the Basketweaving U has an IP address of 192.168.0.15 and has a network mask of 255.255.255.0. All this information (192.168.0.15 and 255.255.255.0) can all be SIMPLIFIED by writing CIDR notation 192.168.0.15/24. This notation tells us that the first 24 bits (that is the 192.168.0) of the IP address is important for the network routing.
So in the end — CIDR notation lets you know how much of the IP address is being used for network routing.
Helpful resource DigitalOcean
