how to check ports on ubuntu code example

Example 1: ubuntu listening ports

# To see ports in use
sudo lsof -i -P -n | grep LISTEN 
sudo netstat -tulpn | grep LISTEN

Example 2: ubuntu check process on port

sudo lsof -i:22

Example 3: linux how to see ports in use

sudo netstat -tulpn | grep LISTEN

sudo lsof -i:22 # see a specific port such as 22

Example 4: see what is using a port ubuntu

$ sudo lsof -i:22