I have a script which loads iptables at /etc/network/if-pre-up.d/iptablesload:


iptables-restore < /etc/iptables.rules

ip6tables-restore < /etc/ip6tables.rules

exit 0

I also have a script which save iptables at /etc/network/if-post-down.d/iptablessave:


# By saving the current iptables rules to the file at the specific path, 
# then they will be loaded on every startup.

echo "Saving current iptables rules..."

iptables-save -c > /etc/iptables.rules
if [ -f /etc/iptables.downrules ]; then
   iptables-restore < /etc/iptables.downrules

ip6tables-save -c > /etc/ip6tables.rules
if [ -f /etc/ip6tables.downrules ]; then
   ip6tables-restore < /etc/ip6tables.downrules

exit 0

I have a file at path /etc/iptables.rules which contains all the rules.

When I manually execute iptables-restore < /etc/iptables.rules then I can see all iptables rules.
But after powering on the PC, then all iptables rules are missing (all is empty).

My conclusion is that the scripts in folders /etc/network/if-post-down.d and /etc/network/if-pre-up.d don't execute. Why?

(The file /etc/iptables.rules exists because I manually executed iptables-save -c > /etc/iptables.rules.)

I'm using the exact same scripts that I used for Ubuntu 18 - they worked well.

The above is originally taken from:

I also tried copying exactly as they write in the link above, but still iptables failed to load.

  • 2
    Correct, they don't execute because the /etc/interfaces file and ifupdown are not used anymore. Ubuntu has switched to networkd, which is just a front end for systemd-networkd. I used to do your method also, and still do on my 16.04 server. I do not like netplan and am doing it now directly with networkd as a post-boot process on my newer server. Nov 30, 2020 at 23:03
  • Please clarify your release(s). Ubuntu uses yy releases only for specialist snap based releases for IoT appliances/devices or cloud based use (having done so since 2016). Main releases use yy.mm such as used by server & desktops releases.
    – guiverc
    Nov 30, 2020 at 23:52
  • @guiverc: Release is 20.04
    – Dor
    Dec 1, 2020 at 23:57
  • Please correct your question, Ubuntu Core 20 and releases using the yy format are different products to yy.mm releases, having been so since 2016
    – guiverc
    Dec 1, 2020 at 23:59

1 Answer 1


It appears that the file you are looking for is now called


sudo cat /etc/iptables/rules.v4
# position 1
# [snip] -- I checked the rules, they are there

So you should be able to

# must be root
sudo -i 
iptables-save > /etc/iptables/rules.v4
ip6tables-save > /etc/iptables/rules.v6

and to restore:

# must be root
sudo -i
sudo iptables-restore < /etc/iptables/rules.v4
sudo ip6tables-restore < /etc/iptables/rules.v6

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