iptables can be saved or loaded from a file. Here’s a way to do it.

Saving to a file

<pre lang="bash">
# Debian/Ubuntu
iptables-save > /etc/iptables/rules.v4
# Redhat/Centos/Rocky
iptables-save > /etc/sysconfig/iptables

Loading from a file

<pre lang="bash">
# Debian/Ubuntu
iptables-restore > /etc/iptables/rules.v4
# Redhat/Centos/Rocky
iptables-restore > /etc/sysconfig/iptables

Listing rules

<pre lang="bash">
iptables -L