Comment 10 for bug 555210

Jeremy,

RFC 3484 specifies the following priorities («IPv6» here implies non-6to4) - it does not matter which is the source and which is the destination:

1) IPv6 <-> IPv6
2) 6to4 <-> 6to4
3) IPv4 <-> IPv4
4) 6to4 <-> IPv6

These haven't changed. However, if you want #4 to be sorted above #3, you can easily accomplish that by disabling the special casing of 2002::/16 by adding the following lines to gai.conf:

label ::1/128 0
label ::/0 1
#label 2002::/16 2
label ::/96 3
label ::ffff:0:0/96 4
label fec0::/10 5
label fc00::/7 6
label 2001:0::/32 7

precedence ::1/128 50
precedence ::/0 40
#precedence 2002::/16 30
precedence ::/96 20
precedence ::ffff:0:0/96 10

If you also want Teredo-based connectivity to be preferred above IPv4, comment out the line with 2001:0::/32 as well.

Tore