Unable to connect to IPv6 from Windows 8.1 via OpenWRT router

Question

I'm new to Ipv6 and trying to learn it. So, I decided to use 6to4 tunneling from Hurricane Electric in my OpenWRT router since my ISP does not provide IPv6. It work perfectly in my router. But when I try ping ipv6.google.com it in my Windows 8.1, it failed with Destination host unreachable. with the following output of the tcpdump in the router:

13:52:39.648512 IP6 2001:470:XX:XXX:XXXX:XXXX:XXXX:XXXX > ff02::1:ff21:c98e: ICMP6, neighbor solicitation, who has fe80::109c:e1ff:fe21:c98e, length 32
13:52:40.234465 IP6 2001:470:XX:XXX:XXXX:XXXX:XXXX:XXXX > ff02::1:ff21:c98e: ICMP6, neighbor solicitation, who has fe80::109c:e1ff:fe21:c98e, length 32
13:52:41.234511 IP6 2001:470:XX:XXX:XXXX:XXXX:XXXX:XXXX > ff02::1:ff21:c98e: ICMP6, neighbor solicitation, who has fe80::109c:e1ff:fe21:c98e, length 32
13:52:43.245871 IP6 2001:470:XX:XXX:XXXX:XXXX:XXXX:XXXX > ff02::1:ff21:c98e: ICMP6, neighbor solicitation, who has fe80::109c:e1ff:fe21:c98e, length 32

The address 2001:470:XX:XXX:XXXX:XXXX:XXXX:XXXX is my Windows 8 as show in Temporary IPv6 Address in the NIC status. And fe80::109c:e1ff:fe21:c98e is my router link local address.

My router can ping Windows 8 with link local address. But Windows 8 cannot ping router with link local address.