Ports
Listening Ports
- Find Out What Ports Are Listening / Open On My Linux & FreeBSD Server
- Various Ways to List Ports on Linux. Option #2 works on barebones machine.
Option #2 for barebones machine:
sudo ss -lntu
Port Binding
Applies to: “Ubuntu 16.04 LTS”
Ubuntu 16 Linux uses authbind
application to control which non-root users can
bind on <1000 port numbers.
Use the following procedure to add new application-port registration.
Example is for port 443 and Jenkins server:
sudo apt-get authbind
sudo touch /etc/authbind/byport/443
sudo chmod 500 /etc/authbind/byport/443
sudo chown jenkins /etc/authbind/byport/443