Failed binding to auth address * port 1812 bound to server default: Address already in use /etc/freeradius/3.0/sites-enabled/default[59]: Error binding to port for 0.0.0.0 port 1812 matthias@ThinkPad-T580:~$

# Stop the service:
systemctl stop freeradius.service
# Make sure systemd thinks it isn't running (see line "Active:"):
systemctl status freeradius.service
# Verify it isn't still running from outside of systemd's managed scope:
lsof -Pni:1812