as a full stack dev, everything you said has offended me.
port 20 is used for FTP, unless you were using FTP, then go right ahead. Guessing that since you didn’t know the protocol you were not using FTP.
port usage reservations are incredibly important to ensure that the system is running within spec and secure. imagine each interface like a party telephone line and the ports are time slots.
your neighborhood has reserved specific times (ports) for everyone to call their relatives. if you use the phone not in your slot (port) your neighbors might get pissed off enough to interrupt your slot. and then it’s just chaos from there.
I never pontificated like that, but you’re utterly correct.
I find it inconceivable that when I stirred from my bedchamber this morning, that I would find myself with an appeal to my senses that would brighten my day.
obliged