Opening.

Hello, couple years ago, I wanted to set and have a static IP, but due lack of knowledge I can't have it. Now I manage to set it and it's kinda work. Here are some methods I'm using.

Methods.

Netplan (Ubuntu & Debian).

I start with netplan. For netplan I just need to make this configuration :

network:
  wifis:
    YOUR_WIRELESS_INTERFACE:
      dhcp4: no
      dhcp6: no
      addresses:
      - x.x.x.x/24
      routes:
      - to: default
        via: x.x.x.x
      access-points:
        "YOUR_SSID":
          password: "YOUR_PASSWORD"
  version: 2
  renderer: networkd

We just need to set the dhcp{4,6} off and assingn the address (for me it's 192.168.x.x) and its gateway (192.168.1.1).

Ifupdown (Ubuntu & Debian).

Besides netplan, we can use ifupdown as well. It gives me old debian memories to be honest. We just need to edit /etc/network/interfaces. This is my simple /etc/network/interfaces file :

auto wlp3s0
iface wlp3s0 inet static
        wpa-conf /etc/wpa_supplicant-wlp3s0.conf
        address x.x.x.x
        gateway 192.168.1.1
        dns-nameservers 8.8.8.8 1.1.1.1

The address and gateway are still same. By the way I also use wpa_supplicant instead of other helper.

Systemd-networkd.

For the last method, I use systemd-networkd. It's quite simple to configure it. All we need is a single file at /etc/systemd/network/, I call it 11-wlp3s0.network. The configuration looks like this :

[Match]
Name=wlp3s0
Unmanaged=no

[Network]
Address=192.168.x.x/24
Gateway=192.168.1.1
DNS=8.8.8.8
DNS=1.1.1.1

It's kinda same, we need to assign wireless interface (for me it's wlp3s0), address, gateway, etc. Don't forget enable and start the systemd-networkd's service !

sudo systemctl enable systemd-networkd
sudo systemctl start systemd-networkd