How do you set up a network firewall?

You can setup your network firewall with your accessing router. consider you are using the Belkin Router : than follow these steps :

Access the Belkin router setup utility via the web browser. For doing that, browse the internet and enter the '192.168.2.1' in the browser's address bar. Click 'Enter' to continue. On the login web page, type your router passWord and click the 'Submit.'

On the setup page, click the 'LAN Setup' menu in the left corner window. Now, you can see the current configuration of the firewall of the router. In Features section, check that the firewall is turned on or not.

Once you assure that the firewall is not enabled, click the 'Firewall' menu to display the firewall settings on the screen. Click the 'Enable' button to select it and then 'Apply Changes' to save your settings.

That's all process allow you to enjoy setup the firewall on the Belkin router and the safety and protection when online or offline.