In this tutorial, How to connect to WiFi ubuntu server on Rasberry Pi  4. Today, I buy Rasberry PI 4 new and install ubuntu 20.04 LTS. root@ubuntu:~# cat /etc/lsb-release DISTRIB_ID=Ubuntu DISTRIB_RELEASE=20.04 DISTRIB_CODENAME=focal DISTRIB_DESCRIPTION="Ubuntu 20.04.1 LTS" root@ubuntu:~#  after finish, Rasberry Pi 4 no identify ip address of wilfi. :D.  Rasberry Pi 4 can't connect to WiFi ubuntu server [fixed] The first, check network interface your system. ll -la /sys/class/net/ Create new file config for wifi " /etc/netplan/wlan.yaml" apply configure and reboot netplan apply The result, as below root@ubuntu:~# ll -la /sys/class/net/ total 0 drwxr-xr-x  2 root root 0 Jan  1  1970 ./ drwxr-xr-x 74 root root 0 Jan  1  1970 ../ lrwxrwxrwx  1 root root 0 Jan  1  1970 eth0 -> ../../devices/platform/scb/fd580000.ethernet/net/eth0/ lrwxrwxrwx  1 root root 0 Jan  1  1970 lo -> ../../devices/virtual/net/lo/ lrwxrwxrwx  1 root root 0 Apr  1  2020 wlan0 -> ../.