kern/44943: 2002::/16 (6to4) addresses are preferred over native IPv6 transport

[pettai%nordu.net@localhost]

>Number:         44943
>Category:       kern
>Synopsis:       2002::/16 (6to4) addresses are preferred over native IPv6 
>transport
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat May 07 13:50:00 +0000 2011
>Originator:     Fredrik Pettai
>Release:        NetBSD 5.99.51
>Organization:
NORDUnet A/S
>Environment:
NetBSD wilma 5.99.51 NetBSD 5.99.51 (GENERIC) #0: Wed May  4 15:19:35 CEST 2011 
 root@wilma:/usr/obj/sys/arch/i386/compile/GENERIC i386
>Description:
NetBSD seems to pref 2002::/16 6to4 addresses (which is a tunnel mechanism) 
over native IPv6 transport if both are given for a remote host. This is broken 
behavior now days, then native IPv6 is deployed on a much wider scale than 
before. (The 6to4 2002::/16 RFC is under discussion to become a historic 
document in the IETF)


>How-To-Repeat:
Fetch a package from a server that has a public DNS name containing a 6to4 
address, a IPv6 native address and a IPv4 address. NetBSD will try to download 
the source file in the order just described.  
>Fix: