Cannot print until I flush iptables

[manorbarndavid2]

I have installed iptables-persistent, done iptables -F, iptables-save to /etc/iptables/rules.v4 and 6, reboot. I find I cannot print on a network connected printer, or log in to my router, but I can access the internet. If I flush iptables again, it all works. If I compare the listing of iptables before and after reboot, they are different. Ubuntu 20.04.1, connected to network by ethernet. How can I fix this

[TheFu]

Look through the rules for issues?
Do you do an iptables-restore /etc/iptables/rules.v4 just after networking is started?

[manorbarndavid2]

If I do the restore after login it does work, but needs sudo to do it, I would like it to happen automatically so my wife as a non-techy can use the system without my help.

[TheFu]

If I do the restore after login it does work, but needs sudo to do it, I would like it to happen automatically so my wife as a non-techy can use the system without my help.

Yes, you should make it part of the network startup steps. In the old days, that was trivial. Just add a post-up stanza to the interfaces file and be done. In the new systemd world, you'll probably want to make a "unit" file and screw with all the dependencies for network startup. No need for sudo at this level. Everything runs as root that way.

[manorbarndavid2]

I am not familiar with the start up at that level, and would appreciate some pointers. Thank you

[TheFu]

https://www.cyberciti.biz/faq/how-to...ntly-on-linux/
The bottom half is systemd.

[manorbarndavid2]

Thank you I will give it a try

[manorbarndavid2]

Still no luck. Booted up, flushed iptables, sudo iptables-save to /etc/iptables/rules.v4 and ip6tables to v6. Reboot, no access to printer or to log in to router. Sudo iptables-restore and ip6tables-restore from the rules files above. Now it all works ok. So the problem seems to be not loading the rules on start up, despite both iptables-persistent and netfilter-persistent both enabled

[TheFu]

How do I say this nicely.

Prove what you are claiming.

Please.

There are all sorts of claims, without any proof provided. From here, it seems that what is being said is

I did everything. It doesn't work.

Please show the proof, step-by-step, for what you've done. Use select/pasted text inside code tags, not images. Nobody can correct issues when images are provided.

[manorbarndavid2]

Yes, I will do that