Operating systems

Windows 7 and 8 IPv6-stack has a nice feature. Every now and then when waking up from sleep/hibernate there is no autoconfigured IPv6-address. It looks like this when checking for IPv6-address with netsh interface ipv6 show address:

Interface 12: WiFi

Addr Type  DAD State   Valid Life Pref. Life Address
---------  ----------- ---------- ---------- ------------------------
Other      Preferred     infinite   infinite fe80::227:10ff:1234:5678%12

Note how there is only link-local address and no "proper" IPv6-address. On Windows 7 there is a fix. Just disable the Teredo-interface:

netsh interface teredo set state disabled

After that IPv6-autoconfiguration works much better. That doesn't do the trick for Windows 8, tough. I have no idea what would help. My only fix is to discard autoconfiguration and manually set an IPv6-address. This setting won't survive a reboot, so it will keep using autoconfig under normal conditions. But anyway, this is what I do to fix my laptop:

netsh interface ipv6 add address "WiFi" 2001:1234:5678:0:227:10ff:1234:5678

After this, netsh interface ipv6 show address will function properly:

Interface 12: WiFi

Addr Type  DAD State   Valid Life Pref. Life Address
---------  ----------- ---------- ---------- ------------------------
Manual     Preferred     infinite   infinite 2001:1234:5678:0:227:10ff:1234:5678
Other      Preferred     infinite   infinite fe80::227:10ff:1234:5678%12

If anybody knows how to fix this, please drop me a comment.