ISSUE 1. User has mIRC automatically connecting to irc.irchighway.net when mIRC starts using Connect at Startup rather than a script. The user is NOT issuing a /server -6 command manually or via a script and mIRC is NOT set to use IPv4 by default.
This is working as intended.
The Windows Winsock API does not resolve IPv6 addresses on IPv4-only systems. It looks like either Microsoft intentionally placed this limitation on the API or it is a Windows bug. The nslookup command actually has to work around this limitation to find the IPv6 address. There is a way to make the API resolve IPv6 addresses on IPv4-only systems but it requires an
administrator DOS prompt and a netsh call.
(Just in case you decided to try out the above netsh call, you can see the current state using "netsh interface Teredo show state", enable IPv6 resolution using "netsh interface teredo set state type=enterpriseclient", and reset it to default using "netsh interface teredo set state type=default").
The reason that /dns defaults to IPv4 is that there is no point in returning IPv6 addresses for users who are on a non-IPv6 system. These addresses would be unusable, unless a user/script has a specific need for it, in which case they can choose to override the default by using /dns -6.
2. A slightly different issue (which might have the same cause) is when you try to connect to a different server that is only IPv4.
This is working as intended.
When you create an IPv4 server window, everything defaults to IPv4, including /dns.
When you create an IPv6 server window, everything defaults to IPv6, including /dns.
If you have IPv6 prioritized in the Ports dialog, everything defaults to IPv6 then IPv4, including /dns.
These behaviours were established a long time ago after much discussion and, as far as I can tell, they are working as intended.
