A firewall is a network security system that serves as your computer’s first line of defense. It monitors any incoming or outgoing traffic and blocks hackers, viruses, and worms that are trying to reach your device over the Internet.
In the CompTIA A+ certification exam objectives 220-901 and 220-902 PDF guide, firewalls are a significant part of the exam. When studying for the certification, you need to refresh your knowledge of firewalls. And what better way to do that than to start with basic firewall best practices? Here they are:
Keep Unnecessary Ports Closed
Only leave ports open that servers and clients require for communicating with the Internet and other networks. You should pay particular attention to the SMTP port or port 25 when connecting to the Internet and only open it for your mail server. Likewise, all servers and clients must transmit emails through a central SMTP server to help prevent compromised clients on networks from spreading potentially malicious emails.
Don’t Forget to Back Up Regularly
Having backups of your recent firewall configuration would save you from a ton of trouble. With every backup, consider what you’ll need for restoring if you have to perform disaster recovery. You should also practice recovery in a testing environment to figure out if there’s anything missing in your backup. This way, you could do a reliable and fast restoration should the need arise.
Always Keep your Firewall Updated
Firewall updates typically include new features and bug fixes that would help in mitigating new threats. Whenever possible, consider updating your network card drivers because these updates usually resolve various issues, even those that at first might not seem related to a malfunctioning firewall.
Review and Update your Firewall Policies Regularly
Your firewall policies would become outdated over time — some services might get relocated to newer servers and servers that were already published online might get taken down. The risk here is the possibility of IP addresses that were used on decommissioned servers being reused on the newer ones. These could then be used for unintended services. You must, therefore, review the policies that clients use for connecting to different Internet services.
Employing these firewall best practices, performing regular maintenance tasks, as well as implementing other network security measures could help ensure the safety of your network. While firewalls help safeguard your systems and networks, they’re one of the many protection layers you need to build and maintain overall protection.