Set a static private IP with systemd-networkd on arch linux

2 min read 25-10-2024

the ifix

Set a static private IP with systemd-networkd on arch linux

In today's guide, we will walk through the process of configuring a static private IP address on Arch Linux using systemd-networkd. This is particularly useful for servers or devices in a network that require a consistent IP address for services to function optimally.

Understanding the Problem

Often, users may find it challenging to set a static IP on Arch Linux, especially if they are accustomed to graphical network management tools. The systemd-networkd service provides a clean and efficient way to manage network configurations directly from the command line.

Original Code Snippet

Here’s an example of the configuration that might cause confusion for new users:

[Match]
Name=eth0

[Network]
Address=192.168.1.100/24
Gateway=192.168.1.1
DNS=1.1.1.1

Rewriting the Configuration

To make it clear and easy to understand, let’s rewrite this configuration into a more structured format while maintaining clarity.

Step-by-step Guide to Configure Static IP

Install systemd-networkd: Ensure that systemd-networkd is enabled on your Arch Linux system.
```
sudo systemctl enable systemd-networkd
sudo systemctl start systemd-networkd
```
Create a Network Configuration File: You'll need to create a .network file in the /etc/systemd/network/ directory. The filename should reflect the interface you are configuring. For example, if you are using eth0, you would create a file named 10-eth0.network.
```
sudo nano /etc/systemd/network/10-eth0.network
```
Edit the Configuration File: Enter the following configuration:
```
[Match]
Name=eth0

[Network]
Address=192.168.1.100/24
Gateway=192.168.1.1
DNS=1.1.1.1
```
- [Match]: This section specifies which network interface the configuration applies to. Replace eth0 with your actual network interface name (you can check by running ip link).
- [Network]: This section specifies the IP address, the subnet mask (in CIDR notation), the default gateway, and the DNS server.
Restart systemd-networkd: Once you’ve saved your configuration, restart the service to apply the changes:
```
sudo systemctl restart systemd-networkd
```
Verify the Configuration: To check if your static IP has been set successfully, use:
```
ip addr show eth0
```
Replace eth0 with the name of your network interface. You should see the static IP address you configured listed.

Additional Explanation

Why Use a Static IP Address?

Using a static IP address can be critical for various network services, including hosting a website, using FTP servers, or running a game server. Static addresses ensure that these services are always accessible at the same address without the risk of changes through DHCP.

Troubleshooting Common Issues

Incorrect Interface Name: Ensure you are editing the correct network interface.
Conflicting IP Addresses: If another device is using the same IP address on the network, you will experience conflicts.
Firewall Settings: Ensure your firewall is correctly set to allow traffic through your configured ports.

Practical Example

Let's say you are running a home server that hosts a web application. By configuring it with a static IP address (e.g., 192.168.1.100), you ensure that you can always access your application via the same URL. This makes it easier to configure port forwarding on your router and share access with others in your network.

Resources for Further Reading

By following this guide, you should now have a static private IP address configured on your Arch Linux system using systemd-networkd. This method is not only efficient but also leverages the capabilities of systemd for seamless network management. Happy networking!