I run a ZeroRPC server and I can connect successfully with a client to the 127.0.0.1 IP. 
However when I use the public IP of the server to the client I get the following error:
zerorpc.exceptions.LostRemote: Lost remote after 10s heartbeat 
I have opened the port from the firewall (using ufw on Ubuntu) but still get the same error. 
Do you have any ideas what the problem might be? 
Thanks!!
What IP address are you binding the server onto? If you want to listen on all interfaces and all addresses, something like tcp://0.0.0.0:4242 should work.
python ZeroRPC heartbeat error on public IP