Hello, I'm tryng to influence the IPv6 Source Address and Destination Address selection, using the prefix policy table. This post describes the problems with the SA selection, in a following post I will describe the DA selection problems. My windows 7 PC receives via Router Adv three global addresses: 2a01:201c:1000:1:x:y:z:t/64 2001:470:b534:1:x:y:z:t/64 2001:1418:20b:1:x:y:z:t/64 I'm tryng to influence the SA choice when connecting to ipv6-test.com (2001:41d0:1:d87c::7e57:1) RFC 3484 for SA selection states that: Rule 1: Prefer same address. Rule 2: Prefer appropriate scope. Rule 3: Avoid deprecated addresses. Rule 4: Prefer home addresses. Rule 5: Prefer outgoing interface. Rule 6: Prefer matching label. Rule 7: Prefer public addresses. Rule 8: Use longest matching prefix. The selected SA when connecting to ipv6-test.com was 2001:470:b534:1:x:y:z:t, as it reflects roule 8 (longest prefix in common between SA and DA) As Roules 1 to Roule 5 are not involved (SA and DA are different, scope is the same, no address is deprecated, no Care-of-address, only one output interface), I expected that introducing a clouse in the prefix policy table I should have been able to change the selected SA. I have changed the policies in this way: C:\Windows\system32>netsh interface ipv6 show prefixpolicies Query sullo stato attivo in corso... Precedenza Etichetta Prefisso ---------- ----- -------------------------------- 60 1 2a01:20c1::/32 50 0 ::1/128 40 1 ::/0 30 2 2002::/16 20 3 ::/96 10 4 ::ffff:0:0/96 5 5 2001::/32 Now the first row matches the SA beginning with 2a01, and the third row matches the destination address (default) both the rows has Label = 1, than I expected that SA= 2a01:201c:1000:1:x:y:z:t should have been selected. But testing the connectivity again SA=2001:470:b534:1:x:y:z:t is always selected. I have tryed in many ways, working with preference, different labels, different prefix lengths, but have not been able to modify the SA selection in any way. The only way is make the router not announcing the 2001:470:: prefix.