Disabling firewall on ubuntu
By default the firewall is turned 'on' on ubuntu server.
When you're inside a corporate network which is already under a corporate-firewall this service is not needed and even can cause problems accessing services that are on the ubuntu server (such as ssh, jenkins and more).
For disabling the firewall on the ubuntu server, run the following command:
sudo ufw disable
In order to turn it on when required, run: sudo utw enable