Recent releases of Raspbian have adopted the use of dhcpcd to manage both dynamic and static interface configuration. If you would prefer to use the traditional /etc/network/interfaces mechanism instead, follow these steps.

  1. First, disable dhcpcd and wpa_supplicant.

     systemctl disable --now dhdpcd wpa_supplicant
    
  2. You will need a wpa_supplicant configuration for wlan0 in /etc/wpa_supplicant/wpa_supplicant-wlan0.conf.

    If you already have an appropriate configuration in /etc/wpa_supplicant/wpa_supplicant.conf, you can just symlink the file:

      cd /etc/wpa_supplicant
      ln -s wpa_supplicant.conf wpa_supplicant-wlan0.conf
    
  3. Enable the wpa_supplicant service for wlan0:

     systemctl enable --now wpa_supplicant@wlan0
    
  4. Create an appropriate configuration in /etc/network/interfaces.d/wlan0. For example:

     allow-hotplug wlan0
    
     iface wlan0 inet static
     address 192.168.2.100
     netmask 255.255.255.0
    
     iface wlan0 inet6 static
     address 2607:f0d0:2001:000a:0000:0000:0000:0010
     netmask 64
    
  5. Reboot to make sure everything comes up as expected. With the above configuration, after rebooting you should see:

     root@raspberrypi:~# ip addr show wlan0
     3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
         link/ether 00:e1:b0:67:98:67 brd ff:ff:ff:ff:ff:ff
         inet 192.168.2.100/24 brd 192.168.2.255 scope global wlan0
            valid_lft forever preferred_lft forever
         inet6 2607:f0d0:2001🅰️:10/64 scope global
            valid_lft forever preferred_lft forever
         inet6 fe80::2e1:b0ff:fe67:9867/64 scope link
            valid_lft forever preferred_lft forever