Best Networkng (Security) OS

[Drate]

I have just about convinced my father to migrate his 4-PC household to Unix/Linux. But more than just a change of pace here, he wants to learn to set-up and administer a secure network environment in a Unix/Linux atmosphere. At present buying Red-Hat is not really an option, or any other OS for that matter, so what OS's/Distro's do yall recommend for Secure Unix/Linux networks that we can download and work on without the financial burden, and still get real experience that could be translated to a real-world, "I wanna get a job doing this sorta thing.", environment?

[zaratustra]

OpenBSD for sure is most secure OS... or if you don't like to make partitions counting sectors with calculator, even FreeBSD would do a great job

[mips]

OpenBSD for sure is most secure OS... or if you don't like to make partitions counting sectors with calculator, even FreeBSD would do a great job

+1 on OpenBSD.

But be warned thoug, it aint no Ubuntu in simplicity. Some things like 3d accelleration wont work either.

FreeBSD is also good, PC-BSD would be a easy intro to freebsd though.

On the LInux from their is the SELinux module.

Maybe buy some books.