Mastering Linux Security and Hardening - Second Edition

Looking at nftables rules in RHEL/CentOS 8 firewalld

RHEL 8 and its offspring use nftables as the default firewalld backend. Every time you create a rule with a firewall-cmd command, the appropriate nftables rule is created and inserted into its proper place. To look at the ruleset that's currently in effect, we'll use the same nft command that we used with nftables on Ubuntu:

[donnie@localhost ~]$ sudo nft list ruleset. . .. . .table ip firewalld {    chain nat_PREROUTING {        type nat hook prerouting priority -90; policy accept;        jump nat_PREROUTING_ZONES_SOURCE        jump nat_PREROUTING_ZONES    }    chain nat_PREROUTING_ZONES_SOURCE {    }. . .. . .[donnie@localhost ~]$

Again, we can see a very lengthy list of default, pre-configured firewall rules. (To see ...