Free Up Port 53 on Ubuntu so custom DNS server can use it

I am implementing a custom DNS server, but when I try using it, it clashes with port 53 being in use.  Changing resolved.config file doesn't help.  My resolved.conf file looks like this: [Resolve] DNS=127.0.0.1 #FallbackDNS= #Domains= #LLMNR=no #MulticastDNS=no #DNSSEC=no My /etc/resolv.conf file looks like this: nameserver 127.0.0.1 nameserver 192.168.1.1 search lan1 Port 53 is still used to resolve DNS... $ sudo lsof -i :53 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE systemd-r 636 systemd-resolve 12u IPv4 22828 0t0 UDP 127.0.0.53:domain systemd-r 636 systemd-resolve 13u IPv4 22829 0t0 TCP 127.0.0.53:domain (LISTEN) When I run the custom DNS Server, I get an error, File "/usr/lib/python3.8/socketserver.py", line 466, in server_bind self.socket.bind(self.server_address) OSError: [Errno 98] Address already in use I would greatly appreciate any advice.