Windows lost IPV6 connection.

[#1]

No idea why it's happening but Windows isn't connecting via IPV6 at the moment.  As the screenshot shows I can ping ipv6.google.com so my router has connectivity so it's something on my Windows side, to me it looks a bit like Windows is being given too many addresses via DCHP or am I totally wrong and missing something?  If it is that, how do I ensure that my router (Cisco 877W) will kill the lease on inactive IPV6 addresses if it needs to?

[#2]

A bit more information would be useful.
Version on Windows?
DNS settings?
dig / nslookup on problem sites?
I am  sure others will have additional questions.
PB

[#3]

Windows 7
DNS is automatic (PlusNet/HE)

Quote

C:\Users\David>nslookup ipv6.google.com Server:  cdns02.plus.net Address:  212.159.6.10 Non-authoritative answer: Name:    ipv6.l.google.com Address:  2a00:1450:400c:c00::67 Aliases:  ipv6.google.com

Quote

C:\Users\David>ping ipv6.google.com Pinging ipv6.l.google.com [2a00:1450:400c:c01::63] with 32 bytes of data: Request timed out. Request timed out. Request timed out. Request timed out. Ping statistics for 2a00:1450:400c:c01::63:     Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

IPV6 test says my connection is not IPV6 capable, but it is, my router is connected via IPV6, wait, I forgot the screenshot didn't I?

[#4]

The screen shot of your network connection details does look odd when compared with mine.
I only have one entry against IPv6 Address.
You do not have any entries against IPv6 DNS servers, I have two, I set my router up for the HE DNS as primary and Open DNS as secondary.
What does a tracert give?
PB

[#5]

Remember that IPv6 connectivity doesn't depend on IPv6-enabled DNS servers when dual stacked - AAAA records can still be obtained over IPv4 so don't let their absence be a red herring.
As Pete suggests, a traceroute would be helpful as would the output of route print (ipconfig /all would also be potentially less ambiguous than the GUI output).
Mathew

[#6]

Rebooting Windows fixed it, I believe the problem is that Windows doesn't realise the IPV6 address it has is no longer valid so instead of release/renew it just adds the IPV6 address which ends up with multiple IPV6 addresses and the ability to use none.  For instance, if I were to issue a reload command on my router it would reboot and issue a new IPV6 address to Windows, Windows would accept the new IPV6 address but not delete the old IPV6 address.
It's the same issue as when I was using HE and switched to PN, Windows still used the HE IPV6 details even though they no longer existed, so I'm thinking it's a bug in Windows.
/edit - I have 2 screenshots, the first is my IPV6 status before a reload command and after, as you can see the router rebooted and dished out a new IPV6 address, but Windows was unable to release the original IPV6 address meaning I'm stuck with a non-working IPV6 (unless I restart the network on my side).  Is the same true with different routers or is this behaviour limited to Cisco?