Answers for "linux listen on port"

linux how to see ports in use

# Any of the following
sudo lsof -i -P -n | grep LISTEN
sudo netstat -tulpn | grep LISTEN
sudo lsof -i:22 # see a specific port such as 22
sudo nmap -sTU -O IP-address-Here

check what ports are open linux

## if you use linux
sudo ss -tulw

used port linux

# Linux
ss -ltn

# windows
netstat -a -p -n tcp | findstr LISTENING

# SOURCE 
https://solace.community/discussion/26/how-to-find-a-free-tcp-port-for-testing-pubsub-with-docker