IP addresses

## What is an IP address? On a network every device has an **IP address**, like a home address. An IPv4 address is made of **4 numbers** separated by dots. Each number is **0–255**: ``` 192.168.1.25 ``` That's **32 bits** in total (4 × 8 bits). ## Private addresses Home, school and office networks use these addresses inside the network: | Range | Example | |---|---| | 10.0.0.0 – 10.255.255.255 | 10.0.5.20 | | 172.16.0.0 – 172.31.255.255 | 172.16.1.10 | | 192.168.0.0 – 192.168.255.255 | 192.168.1.25 | Most other addresses are **internet (public)** addresses. ## Watch out - Two devices on the same network can't have the **same IP** — that causes an "IP address conflict". - `192.168.1.300` is wrong — 300 is bigger than 255. > 🎮 **Network lab → Task 2**: give a computer an IP and ping it. > > 🧮 Problems: **Networks → Level 4**