Mastering Linux Security and Hardening - Third Edition

5

Securing Your Server with a Firewall — Part 2

In Chapter 4, Securing Your Server with a Firewall - Part 1, we covered iptables and nftables, which are management utilities that directly interface with netfilter. Although it’s helpful to be familiar with iptables and nftables commands in order to create advanced firewall configurations, having to use these commands all the time can become a bit unwieldy for performing normal day-to-day operations. In this chapter, we’ll look at ufw and firewalld, which are helper utilities that can simplify the process of working with either iptables or nftables.

First, we’ll look at the Uncomplicated Firewall, or ufw. We’ll look at its structure, its commands, and its configuration. Then, we’ll do the same ...