Installer Feature Request: Add an option to manually disable IPv6 by calling dhcpcp -4

Hello!


Today, I was testing the with the NetBSD installer inside a QEMU VM.
It was not my first encounter with NetBSD, and I was simply playing around
with the options. (You know... They kind of things you do on a sunday... 
;) )

As a user, I encountered a rather frustrating problem with using HTTP as
installation source, namely the timeout for the IPv6, which.
takes.
for.
ever.


I was already told (by netbsd-bugs@) that this issue has been discussed 
before,
and that the consensus is that the blame lies at the badly configured VM 
host.

BE THAT AS IT MAY, and as admirable as insisting on proper IPv6 
discipline is:
It is frustrating as HELL for a casual NetBSD user like me.

The easiest Hotfix I could think of would be disabling IPv6 inside the 
installer,
IF THE USER WANTS IT. I have not have a look at the source of the installer,
(yet, i do not know where they are.... casual user... ), but my 
instincts as a
developer tell me that it should be possible to add an option such as
"autoconfigure IPv6" and "autoconfigure IPv4 only" to it somewhere. The
former would then run "dhcpcd" in the background, whilst the latter calls
"dhcpcd -4".



AGAIN: This seems to be the easiest hotfix for a casual user like me, who
just starts venturing out into the NetBSD world. If there is a technical
dependency on the IPv6 policy, then I apologize for the time wasted when
you read this email.  If it is a compromise between several political views
and the outcome of a debate, then it is a rather poor one (from a user's
perspective).

If you are interested in replicating the problem, please let me know.


Thomas