[v6ops] Microsoft Win10 source address selection woes

[Mikael Abrahamsson <[e-mail]>]

I am finding interesting behavior with my fully updated Win10. It seems to 
prefer "public" address over temporary, which doesn't seem to follow 
RFC6724. These addresses are all in the same /64, I am running with A=1.

(obfuscated some fields)

>netsh int ipv6 sho addr

Interface 6: Ethernet

Addr Type  DAD State   Valid Life Pref. Life Address
---------  ----------- ---------- ---------- ------------------------
Temporary  Deprecated    5d2h5m1s         0s PREFIX:8403:XYZ:f15e:d720
Temporary  Preferred    6d2h3m27s    2h1m57s PREFIX:a910:XYZ:ef8e:3484
Public     Preferred  29d23h57m11s 6d23h57m11s PREFIX:c16d:XYZ:XYZ:a45c
Other      Preferred     infinite   infinite fe80::c16d:fb79:XYZ:XYZ%6

Now, when I use web browsers (firefox/chrome/edge) they all use the public 
address for outgoing connections. This is not what I expected (and not 
what I see on my MacOS machine).

RFC6724 rule 7 seems it should indicate that temporary address should be 
chosen. However, RFC3484 says public addresses should be chosen over 
temporary ones, unless specific API calls are made.

Does this mean Windows 10 doesn't implement RFC6724 but instead implements 
3484?

-- 
Mikael Abrahamsson    email: [e-mail]