The portmaster firewall catches SSH with IPv6 when connecting to my public ISP on the WAN

[Zesko]

I know now after my investigation. systemd-resolve caused this.

It is related to the tip I had followed a long time ago:

[root tip] [How To] NordVPN on Manjaro

Difficulty: ★☆☆☆☆ NordVPN on Manjaro From my notepad NordVPN on Arch based distribution | root.nix.dk What this topic is not This is not a topic on installing NordVPN But what is it It is a topic on setting up Manjaro to ensure the nameserver settings is restored on disconnecting NordVPN and a topic describing how I did the troubleshooting. Assumptions and prerequisite You have installed nordvpn using the custom package nordvpn-bin You have added yourself to the group nordvpn verify usin…

My solution:

1. Delete the symlink /etc/resolv.conf for systemd-resolved.

2. Disable systemd-resolved.service.

3. I restore my old resolv.conf from my backup. However, it could be generated by networkmanager as the dependency required by KDE.

The SSH IPv6 connection to my private NAS always remains in my private LAN after DNS resolving on my private router after each reboot, that is my expectation.

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Edit:

That looks like systemd-resolve --status shows that ISP’s DNS with IPv6 support is used as the current default DNS server after reboot.

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Edit2:

Another solution is also possible if you want to continue using systemd-resolved

The portmaster firewall catches SSH with IPv6 when connecting to my public ISP on the WAN

You can specify the order in a file in /etc/systemd/network/<nic>.network The following is from memory - perhaps my memory is not as good as I hope - I will verify it. [Network] DNS=192.168.1.0 Domains=mynet.lan This should ensure that all hostnames on mynet.lan is resolved using the local dns. Just checked with the Arch Wiki. A better approach seems to be to edit /etc/systemd/resolved.conf.d/dns_servers.conf https://wiki.archlinux.org/title/Systemd-resolved#Manually Example [Resolve] DN…