Win7 & ULA prefix selection policy

[Tassos Chatzithomaoglou]

After experimenting a little with ULAs, i noticed that Win7 uses ULA as source in order to connect to a global IPv6 address, while at the same time destroying the quick switchover effect of HE. Linux on the other hand doesn't seem to suffer from the same issue.

I did a quick search and i found out that this is expected behavior, so a solution from MS shouldn't be expected any time soon (although there is a workaround by changing the prefix selection policy).

C:\Users\Tassos>netsh interface ipv6 show prefixpolicies
Querying active state...

Precedence  Label  Prefix
----------  -----  --------------------------------
        50      0  ::1/128
        40      1  ::/0
        30      2  2002::/16
        20      3  ::/96
        10      4  ::ffff:0:0/96
         5      5  2001::/32


Latest rfc 6724 defines a specific policy for ULAs, while the older one rfc 3484 didn't:

      Prefix        Precedence Label
      ::1/128               50     0
      ::/0                  40     1
      ::ffff:0:0/96         35     4
      2002::/16             30     2
      2001::/32              5     5
      fc00::/7               3    13
      ::/96                  1     3
      fec0::/10              1    11
      3ffe::/16              1    12

Does anyone know if MS has any plans to implement the newer RFC? It's almost a year since the RFC came out.
Dave as an author might be a hint, but i have seen many similar cases without the expected result.


-- 
Tassos