IPv6 Support

[josh-tuik]

Greetings, Thanks for a great app.

After upgrading to v2, I'm getting timeout errors when attempting access to inigo-settings.txt with a hostname that resolves with an IPv6 address. Because my WeeWx host is dual-stacked, I can replace the hostname with the IPv4 address and connectivity is restored without timeout. v1 doesn't seem to have this issue.

[evilbunny2008]

I have my hobby weather site proxied over a Cloudflare tunnel and the app was coded to prefer and try IPv6 first, although it should fall back to IPv4.

If you turn on debug logging in settings then click save that might offer clues as to what failed, the file is saved in Downloads/weewx/* as a gzipped text file.

[josh-tuik]

Thanks for the debug suggestion. I'll relay some logs when I test it out. Initially, the app hangs when I enable this but I might also be fighting with an ancient version of Android and/or permission issues.

[evilbunny2008]

Not sure if this applies or not, but of late I noticed problems with various apps on Android not connecting to ULA IPs on my LAN from re-written DNS replies for servers.

It turned out because I didn't have the subnet being announced in RA packets Android was using a routable IP and the router was forwarding packets to the server but the replies were somehow being lost in the router on the way back.

Once the router was announcing the subnet and Android was using an IP from the ULA subnet all the problems went away.

[josh-tuik]

Thanks for the added experience/behavior. I did some additional experimentation. I think I'll close my issue based on my results.
IPv6 client (app) to IPv6 server (weewx) on the same subnet works.

I get some interest results when I have the client on an IPv4 subnet and it attempts to traverse a firewall into a dual-stack subnet with the server, with some oddities between http and https. http times out at "save settings", but works to refresh data ongoing and makes the expected web hits. https gives an error that includes the IPv6 address in the message when it really shouldn't because it should only be operating with IPv4; and never refreshes like http. I could go into further detail, but I don't think my uniquely configured environment is something you should waste any cycles on.

My only take-away is that the v1 app seemed to handle all this seamlessly.

[evilbunny2008]

How can it route IPv6 packets if the network it's on is IPv4 only?