[BBLISA] task and port number?

[Scott Ehrlich]

On a Linux system, if a program claims that a port is in use (say I want to 
install a web server on port 80, but the web server claims port 80 is already 
in use, and a ps auwx doesn't show/claim a web server is running), is there a 
program that can tell me what application is using the port?

Yes, nmap will show ports, but the apps it shows are part of its own built-in 
database or /etc/services, so the app report isn't accurate.

netstat -a will show apps and their PIDs, then later what ports are open, but 
no direct port <-> app mapping.

Maybe there is a compilation of ssh server designed to listen on port 65530, 
and the daemon name is something I wouldn't expect, or it is invoked by some 
other application.

What tool can I use for real-time port <-> app mapping?

Thanks.

Scott