====== Set up iptables ======

===== Check rules =====

The following command lists all valid rules for iptables:

<code bash>
iptables -L
</code>

===== Save rules to a file =====

<code bash>
apt-get update
apt-get install iptables-persistent
nano /etc/iptables.test.rules
^O
^X
</code>

The iptables.test.rules file can now be edited.

===== Define rules =====

[[linux:firewall_rules|iptable rules]] can now be defined accordingly.

===== Activate rules in productive operation =====

<code bash>
iptables-save > /etc/iptables.up.rules
nano /etc/network/if-pre-up.d/iptables
^O
^X
</code>

The file /etc/network/if-pre-up.d/iptables is executed at system startup and loads the corresponding firewall rules. The following lines must be inserted here:

<code bash>
#!/bin/bash
 /sbin/iptables-restore < /etc/iptables.up.rules
</code>

Now make the file executable and that's it:

<code bash>
chmod +x /etc/network/if-pre-up.d/iptables
</code>