Understanding IP Addressing & Subnets

Before configuring interfaces, you must understand the "address space" of your network. This is the foundation for all routing and VPN configurations.

1. The Anatomy of an IP

An IP address (IPv4) consists of four octets (e.g., 192.168.88.1). The subnet mask determines which part of that address is the "Network" and which part is the "Host."

2. What is a Subnet?

A subnet (e.g., /24) defines the size of your network. A /24 subnet allows for 254 usable devices. If your VPN tunnel uses 10.0.0.0/24, your gateway is usually 10.0.0.1.

The Golden Rule of Routing

Your VPN interface cannot share the same subnet as your local LAN. If your LAN is 192.168.88.0/24, your VPN tunnel mustuse a different range, like 172.16.0.0/24.

Next Steps

With address space understood, proceed to: