Linux is highly secure, but you should still have a firewall. You should know if your ISP's hardware (gateway) uses a firewall. One of the easiest Linux firewalls is UFW and its GUI sidekick, GUFW.
In January 2000, Check Point Software introduced a Linux port of its flagship product, FireWall-1. FireWall-1 is one of the best-selling products in the commercial firewall market. It now runs on five ...