Ravi Sir's Cyber Security Cards › Revision Cards
Subnetting Basics (Worked Example)
Subnetting Basics (Worked Example) Subnetting means splitting one network into smaller networks (subnets). Network: 192.168.10.0/24 . Need 4 equal subnets for 4 labs. 4 subnets need 2 more bits (2² = 4). New size: /24 + 2 = /26 . Each /26 has 64 addresses: .0, .64, .128, .192. Put web servers in a p
Read card text
What this card says
What it is
Subnetting means splitting one network into smaller networks (subnets).
Worked example
Network: 192.168.10.0/24. Need 4 equal subnets for 4 labs.
4 subnets need 2 more bits (2² = 4). New size: /24 + 2 = /26.
Each /26 has 64 addresses: .0, .64, .128, .192.
Why it matters for security
Put web servers in a public subnet and databases in a private subnet.
If one web server is hacked, the attacker cannot easily move to the database.
| Subnet | Network address | First usable |
|---|---|---|
| Lab 1 | 192.168.10.0/26 | 192.168.10.1 |
| Lab 2 | 192.168.10.64/26 | 192.168.10.65 |
| Lab 3 | 192.168.10.128/26 | 192.168.10.129 |
| Lab 4 | 192.168.10.192/26 | 192.168.10.193 |
Learn more in the lesson: 1.5 Subnetting Basics (Worked Example)