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How to streamline networking on linux

How to streamline networking on linux

luffy luffy
June 25, 2025
3 min read
linux networking
index

Networking on Linux can get confusing because there are many different tools to manage it. Tools like ifupdown, NetworkManager, and systemd-networkd can all be used — but mixing them can create conflicts.

since i am setting up debian 12 as my base OS for my homelab cause ubuntu is a bloat, we will clean up the networking setup on Debian and configure it properly using systemd-networkd for managing the network and systemd-resolved for DNS. This keeps everything simple and easy to troubleshoot.

Understanding How Different Systems Work

Before we get started, let’s clear up how different distros handle networking:

Ubuntu Server & Ubuntu AMI (Cloud)

  • Uses netplan with systemd-netwrokd, Netplan generates the required config in /etc/netplan/50_cloudinit.yaml. which can be used by systemd-networkd.

Most Linux Desktop

  • Uses NetworkManager by default.

Debian

  • Offers options like:

    • ifupdown (older method)

    • NetworkManager

    • systemd-networkd (modern, lightweight)

We will go with systemd-networkd because it’s simple, clean, and good for servers or homelabs.

Step 1: Install Required Tools

Most likely, systemd-networkd is already installed on Debian, but to be sure:

Terminal window
sudo apt update
sudo apt install systemd-networkd systemd-resolved -y

Step 2: Remove Unnecessary Tools

First, let’s get rid of any tools we don’t need:

Terminal window
sudo apt remove --purge ifupdown network-manager net-tools -y
sudo apt autoremove --purge -y

check if any leftover packages remain:

Terminal window
dpkg -l | grep -E 'ifupdown|network-manager'

If you see anything, purge it.

Step 3: Enable systemd-networkd and systemd-resolved

Terminal window
sudo systemctl enable systemd-networkd --now
sudo systemctl enable systemd-resolved --now

Check if they’re running:

Terminal window
systemctl status systemd-networkd
systemctl status systemd-resolved

Tip: To properly use resolvectl, make sure /etc/resolv.conf points to systemd’s resolver:

Terminal window
sudo ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf

Step 4: Configure the Network

All configs for systemd-networkd live in /etc/systemd/network/.

4.1 DHCP Example (Automatic IP)

Create a file like 10-ethernet.network:

Terminal window
sudo nvim /etc/systemd/network/10-ethernet.network
[Match]
Name=enp1s0f1  # Change this to your interface name


[Network]
DHCP=yes

4.2 Static IP Example

[Match]
Name=enp1s0f1


[Network]
Address=192.168.1.50/24
Gateway=192.168.1.1
DNS=1.1.1.1

After creating the config, reload:

Terminal window
sudo systemctl restart systemd-networkd

Step 5: Basic Troubleshooting & Commands

Terminal window
networkctl status enp1s0f1

5.2 Show IP Addresses

Terminal window
ip a

5.3 Show Routes

Terminal window
ip route show

5.4 DNS Status

Terminal window
resolvectl status

5.5 Test Connectivity

Terminal window
ping 8.8.8.8
ping google.com

Managing DNS with systemd-resolved on Debian

Since we are now using systemd-resolved, our /etc/resolv.conf is a symlink managed by systemd. So, we don’t edit it manually. Instead, we manage DNS settings properly using tools and configuration files.

✅ Temporary DNS Change

This change is temporary and will reset After a system reboot or After restarting systemd-networkd

Command:

Terminal window
resolvectl dns <interface> <dns-address>

Example:

resolvectl dns enp1s0f1 1.1.1.1

To Verify:

resolvectl status

✅ Permanent DNS Change

To set DNS permanently, edit your .network configuration file inside /etc/systemd/network/xyz.network

Example of Static IP + DNS:

[Match]
Name=enp1s0f1


[Network]
Address=192.168.1.50/24
Gateway=192.168.1.1
DNS=1.1.1.1

Apply the changes:

sudo systemctl restart systemd-networkd

✅ Using DHCP but Custom DNS (Ignore Router DNS)

Even when using DHCP for automatic IP configuration, you can override the DNS provided by your router.

[Match]
Name=enp1s0f1


[Network]
DHCP=yes
DNS=1.1.1.1

Apply the changes: sudo systemctl restart systemd-networkd

so now to manage DNS, temporary way is using resolvectl dns <interface_name> 1.1.1.1 , but to make it permanent we can simply edit our network file /etc/systemd/network/10-wired.network file and define dns or other paramethers directly and simply restarat systemd-networkd