Rock-solid FreeBSD – HardenedBSD

Before exploring OPNsense, let's look at its kernel: the almighty FreeBSD, the operating system that has the power to serve!

FreeBSD

First, FreeBSD isn't Linux! If you are a long-time FreeBSD user, don't be mad with me, as you probably have heard this statement before! If not and you thought that FreeBSD and Linux were the same, no problem! That is a common mistake people make. Let's first find out what FreeBSD is in a short introduction.

FreeBSD is a free and open source operating system. It is a Unix-like system but different from Linux; it is a complete operating system, including the kernel, drivers, and other user utilities and applications. Linux only includes the kernel and drivers, and everything else is built as the distribution or just distro. The FreeBSD project has an outstanding security reputation, and it has a dedicated team taking care of this at the code level. This has built a well-known reputation for a very secure operating system!

If you have never installed FreeBSD before, you must be thinking that you will use it for the first time on OPNsense, right? Not necessarily! You have probably used FreeBSD a lot already. Don't believe me? One of the strong points of the FreeBSD project is its licensing model, which is considered permissive. Add to that the system liability, robust security, and good hardware support and you have a lot of reasons to choose FreeBSD as your new product base operating system. Many companies have – Apple's macOS, iOS, and other OSes are based on FreeBSD code, Sony PlayStations 3 and 4 use it, and many network appliances make use of it too! If you have an iPhone, that also runs a FreeBSD-based operating system!

Now that we are introduced to OPNsense's operating system, let's explore why we should consider it for our network firewall.