Give your Raspberry Pi a static IP address

Mar 5, 2020

Learn how to give your Raspberry Pi a fixed LAN IP by setting up a static DHCP lease on your router, bound to the Pi's MAC address that you find with arp.

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I recently got a Raspberry Pi for testing, and to build some projects ideas I have, and right after installing Raspbian, the Linux version of Debian specifically made for the Raspberry Pi, I had a problem.

I attached the Raspberry Pi to the TV, using the HDMI cable, and I attached an USB mouse and USB keyboard to install the OS and get all “wired up”.

I then set up the VNC Server on the Pi to be able to connect to it from the Mac.

As I was removing all those cables, so that only the Raspberry Pi was left attached to the power cable, I realized that as soon as I restarted it, the IP address assigned to it would change.

This is because of DHCP, the protocol that is used by the WiFi router. It does not assign a fixed IP to every device connected: the IP changes all the time.

Sometimes it’s 192.168.1.2. Sometimes it’s 192.168.1.30. Sometimes it’s 192.168.1.43.

I don’t really want to spend time every time to find what’s the Raspberry Pi IP address, right? It’s annoying.

By the way, all those 192.168.1.x addresses come from your router’s subnet. If you want to understand how IP ranges and netmasks work, I built a free CIDR calculator that shows it visually.

So I found out that I can assign a fixed IP to a specific device, by identifying its MAC address. The MAC address, aka Media Access Control Address, is a unique identifier. Every device has a different one.

So I connected to my WiFi router, which is running on IP 192.168.1.1 on my local network, and I went to the DHCP Server menu.

In there, I clicked “Static DHCP” and I was able to assign a specific IP to the MAC address of my Raspberry Pi:

The Router Admin Panel

How did I find the MAC address of the Pi?

I knew the IP address because the VNC Server panel on the Raspberry Pi showed it:

The VNC Connect panel

Then using my MacBook Air I scanned the network using:

ifconfig | grep broadcast | arp -a

This printed the IP and MAC addresses of all devices connected to the network, including the one I was interested in, the Raspberry PI:

? (192.168.1.42) at dc:a6:32:60:20:81 on en0 ifscope [ethernet]

Tagged: Computer · All topics

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