Debian 'ignores' /etc/network/if-pre-up.d/iptables

Solution 1:

This problem might be related to the permission bits of your script. What is the output of this command? Does it include your file?

run-parts --test /etc/network/if-pre-up.d

Solution 2:

Use the iptables-persistent package for this task.

Define your rules in /etc/iptables/rules.4 and /etc/iptables/rules.6 and don't forget to activate the service (using update-rc.d, chkconfig or you favourite tool.