We can configure the following debugging parameters in tomcat/bin/catalina.sh for debugging when developing and deploying tomcat locally:

But the same configuration on the remote server will give an error at the beginning of debugging:

Check remote configuration:

The IP and port number are correct, but the connection is denied, so we check the server port 16808:

As you can see, the current 16808 port service is bound with a loopback address, which is inaccessible to the outside. It shows that if the address in JAVA_OPT does not specify an ip, it will be bound to this machine by default. If it is a project that provides remote debugging on the server, you need to specify the current server address, and the problem will be solved.