Setting to force IPv4/disable IPv6

[CRC-Mismatch]

I feel the lack of a way to force HexChat to connect via IPv4 only, maybe on a per-server basis, possibly via a global setting.

I couldn't seem to find a way to do this messing only with HC. Basically, I wanted it to connect to one server via IPv4 in order to enable sending files via XDCC. I would be fine if I had to connect to all servers in this manner (for now I only use one, and probably IPv4 would do fine for all servers).

The best workaround I could find is to set the "DCC IP address" to my current remote IP, but since it's dynamic, I would have to change it every time - and also it seems to then fail due to the port chosen not being forwarded via UPNP, which would force me to set a port range and forward it...

I could disable IPv6 entirely for the adapter, but I want to still be able to use it where I need (more like can use) it, and that wouldn't be a "portable" way of doing it as it's related to the OS...

[CRC-Mismatch]

After tinkering about, I noticed that this would solve the "not being able to get the remote IP from the server" part, but still wouldn't help without forwarding ports and setting a fixed range...

[TingPing]

So the entire concept of "getting your IP from the server" is a rather dumb and broken one as most networks don't reliably report this information.

There aren't a ton of ways to reliably get this information; One method is upnp which when your router knows your address it works fairly well in my tests but the problem there is it fails when using proxies or vpns, alternatively we can have a remote service to query for what our address appears as but that requires somebody hosting a service.

So using either of those methods the issue of what protocol you use to connect the IRC server really doesn't matter at all. (Also we should be at the point where DCC works over IPv6 ideally).

[learn-more]

https://www.ipify.org/

[TingPing]

Oh and either solution requires HexChat to add a dependency, be it just libsoup for http or gupnp.

[CRC-Mismatch]

I guess the easiest way out would be as hard as implementing a way to enable reverse DCC like the one that mIRC and KVirc implement, where the SEND message has 0 for port and a token int as an extra parameter. I was able to get sucessful transmissions when testing these even when I sent in a bogus or 0 value for IP address, since the receiving end sends back their own IP and port via CTCP in a mirror SEND request, and then the listening gets delegated to the opposite side. Not only would this solve port forwarding and NAT problems, but also VPN and CGNAT.

[TingPing]

Pretty confident HexChat already supports that.

[rcmaehl]

Also having this issue, unable to connect to some servers such as Espernet with IPv6 enabled

[Mikaela]

I think this might be a duplicate of #1309 (which should probably be called as "Happy Eyeballs" or similar I see that TingPing renamed it from that) or it could be duplicate of this, but I still believe that disabling IPv6 is the wrong solution.

[EduFrazao]

In a Dual Stack enviroment, when IPv6 fails for some reason, (for now, I have problems to reach ipv6 at freenode, but ipv4 is fine), there is no ipv4 fallback, like WebBrowsers do?

[ghost]

There is ipv4 fallback. I have just observed that with tcpdump.

However, there is no message about that in the Server log.