ubuntu open tcp port

 https://stackoverflow.com/questions/30251889/how-can-i-open-some-ports-on-ubuntu

check currently open ports:

sudo ufw status verbose

open ports:

allow range :

ufw allow 11200:11299/tcp

allow one:

sudo ufw allow 22/tcp


Note: docker-compose usally opens up tcp ports for external then forward request
to container ports through -ports: 8000:8000. If no external policy prevents it

Howver, web server like apache/Gin needs especifically do it using ufw if not using docker