What you will learn
- Read CIDR notation
- Calculate subnet ranges
- Plan an address space
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The basics, in plain English
Every device on a network needs an address so data knows where to go, just like a postal address. That address is an IP address. Subnetting is just the trick of splitting one big block of addresses into smaller, organized groups.
- IP address
- A unique number assigned to a device on a network, like 192.168.1.10, used to find it.
- Network vs host
- Part of the address names the street (the network); the rest names the specific house (the device).
- Subnet
- A smaller block carved out of a bigger address range, used to group and isolate devices.
- CIDR ( /24 )
- A shorthand like /24 that says how many addresses are in a block. Smaller number = bigger block.
- Private vs public
- Private addresses only work inside your own network; public ones are reachable from the internet.
01
CIDR
10.0.0.0/16 means the first 16 bits are the network. The remaining bits are hosts. Subnetting splits a block into smaller ones for isolation.
Try it yourself
text
10.0.0.0/16 -> 65,536 addresses↳A /16 leaves 16 host bits, so 2^16 addresses.10.0.1.0/24 -> 256 addresses↳A /24 leaves 8 host bits, so 2^8 addresses.10.0.1.0/28 -> 16 addresses↳A /28 leaves 4 host bits, so 2^4 addresses.↳ lines explain what each command does — only the commands get copied
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