In this chapter, we've looked at four different frontends for the netfilter firewall. We first looked at our trusty old friend, iptables. We saw that even though it's been around forever and still works, it does have some shortcomings. We then saw how Ubuntu's Uncomplicated Firewall can vastly simplify setting up an iptables-based firewall. For you Red Hatters, we looked at firewalld, which is specific to Red Hat-type distros. Finally, we wrapped things up by looking at the latest in Linux firewall technology, nftables.
In the space allotted, I've only been able to present the bare essentials that you need to set up basic host protection. But, it is at least enough to get you started.