Configuring the firewall

- [Instructor] A firewall is software that protects the…system from unwanted network connections.…Here at Ubuntu, we can enable the firewall and…manage it easily with UFW,…which stands for uncomplicated firewall.…UFW manages rules for the…iptables packet filtering software.…And makes it somewhat easier to manage them…than if you had to deal with them directly.…By default UFW blocks any incoming traffic that…isn't associated with outgoing requests.…So in order to not cut off our own access here,…we'll need to add a rule allowing it.…

SSH uses port 22 and the tcp protocol.…So to create a rule,…I'll write UFW allow 22/tcp.…That lets traffic destined for port 22…through the firewall.…So it can be used by the SSH server.…When you start up a service that uses a port on your server,…you'll need to open up that port on the firewall if you…want other systems to be able to connect to it.…With our one rule in place let's start up the firewall.…

I'll write uwf enable to start it up.…And I can take a look at the rules with ufw status.…