webmin/nftables/help/intro.html

<header>Introduction</header>
<p>nftables stores firewall rules in tables. Each table belongs to a family (such as <tt>inet</tt>, <tt>ip</tt>, or <tt>ip6</tt>) and contains one or more chains. Chains contain rules, and each rule is a sequence of tests (matches) followed by an action like <tt>accept</tt>, <tt>drop</tt>, <tt>jump</tt>, or <tt>log</tt>. Named sets can group addresses or services for reuse in multiple rules.</p>
<p>Rules are stored in the system's nftables configuration file &mdash; <tt>/etc/nftables.conf</tt> or <tt>/etc/sysconfig/nftables.conf</tt>, whichever the <tt>nftables</tt> service loads on this system. Top-level comments, <tt>define</tt> variables and <tt>include</tt> lines remain in their original positions. A table changed through Webmin may be rewritten in a normalized form. The <tt>nftables</tt> service loads that file at boot, so rules saved here survive a reboot in the same way as rules written by hand.</p>
<p>To get started, use the Setup page to create a default ruleset, or create a table and chain manually. Then add rules (and sets) from the table view. When you are ready to activate your changes, click Apply Configuration to load the ruleset into the kernel.</p>
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