A firewall is a piece of software or hardware that can help protect your computer against hacker attacks, such as computer viruses. A firewall helps to screen out many kinds of malicious Internet traffic before it can reach your computer.
Turn on Mac firewall
Mac OS X has a built in firewall. Follow these instructions to ensure this firewall is turned on.
- Go to Applications > System Preferences
- Under “Personal“, click on “Security & Privacy“
- Click on the tab labeled “Firewall“
- Click the “Turn On Firewall” button to enable your firewall.