NetworkManager: Use a wired connection to join a domain

On Linux computers running NetworkManager: Before joining a domain, ensure you have a wired network connection configured to start automatically when plugged in. Use this wired connection throughout the join process, including the restart and first domain login.

After your first AD domain login over a wired connection, you can switch back to wireless; your credentials are cached. Note that password expiry notifications require either a wired connection or running a sudo command.

If you join the domain over a wireless connection, AD login will fail after restart.

Here is why: NetworkManager runs as both a startup daemon and a user-mode application (launched at logon). Wireless connections aren't detected until the user-mode application starts which means wireless isn't available until after you log on.

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For more information about NetworkManager, see GNOME Project Handbook.