Configuring a wifi access point on ubuntu server with netplan

This is practical for home servers and personal infrastructure. It is unlikely to be relevant for production environments.

Why would we need an access point on a server?

• We get an additional layer of security by assigning a dedicated IP range to access point clients via DHCP. We can then use firewall rules to restrict certain services to only those addresses.
• We get a backup connection channel to our home server when the main router is down for any reason.
• Our home server can operate without intermediate devices. This makes it more portable — we can take it on a business trip (if it is compact) and access our data without a travel router or hotel network.

Installing the required package

sudo apt-get install network-manager

Getting the name of a WiFi device

ls /sys/class/ieee80211/phy0/device/net/

Adding a configuration section to the netplan config

  renderer: NetworkManager
  wifis:
    wlx90de80f97ff1: # Replace with your wifi device name
      optional: true
      dhcp4: true
      addresses: [192.168.10.1/24] # DHCP ip range
      access-points:
        "drx3": # Wifi network name
          auth:
            key-management: psk
            password: "testpw" # Use a stronger pw
          mode: ap
          band: 5GHz
          networkmanager:
            passthrough:
              wifi-security.proto: "rsn"

Applying the new AP config

sudo netplan apply

Now we can connect to our home server directly via WiFi.