Ubuntu Server 20.04 on Raspberry Pi 4: WiFi configuration from terminal with Netplan

netplan.md

List the network devices.

$ ls /sys/class/net
eth0  lo  wlan0

Edit the config file.

$ vi /etc/netplan/50-cloud-init.yaml
# This file is generated from information provided by the datasource.  Changes
# to it will not persist across an instance reboot.  To disable cloud-init's
# network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
network:
    ethernets:
        eth0:
            dhcp4: true
            optional: true
    version: 2
    wifis:
        wlp3s0:
            optional: true
            access-points:
              "SSID-NAME-HERE":
                password: "PASSWORD-HERE"
            dhcp4: true

Apply the config.

$ sudo netplan apply

Reboot.

How to configure multiple access points? I have 2 SSIDs and wanted to configure so that if one goes down the other one is picked up.

Please refer to netplan documentation. I think if you configure both the failover should trigger automatically.

I am using my college wifi which requires additional authentication along with a wifi login, in which you have to enter your college user id. How should I modify the yaml file.

Please refer to the netplan documentation. If still not sure, please reach out to the maintainers.