Disable IPv6 by default.

[Chuck Anderson]

On Thu, Sep 13, 2007 at 09:02:16AM -0600, Richi Plana wrote:
> Isn't there a way to determine at boot-time whether the network
> infrastructure the computer is on actually supports IPv6 or not? For
> ubiquitous protocols like IPv4, it isn't needed, but for IPv6, it just
> makes more sense. The question is, is it possible to determine it in a
> continuous manner? Kind of like hot-plugging. Maybe a check can be
> performed everytime an interface goes up (assuming it CAN be detected).

Yes, the system sends out IPv6 Neighbor Discovery messages and listens 
for IPv6 Router Advertisement messages.  This all happens 
automatically by default in Fedora thanks to the hard work that has 
gone into enabling IPv6 by default in the OS, applications, and 
services.  If you are on a network that supports IPv6, it all Just 
Works(TM), just the same as IPv4 has up to this point.

> If it isn't used, then free up the unused resources.

IMHO the resource argument is a red herring.  Perhaps we should not 
ship GNOME by default because it uses too much resources?  OTOH, 
perhaps we should disable IPv4 by default, or free all kernel 
resources related to IPv4 if there is no response from an IPv4 DHCP 
server?  I don't think these are very good arguments.