Windows 7: Issue with Windows 7 pinging XP box's Local Link IPv6 address

I am having an issue trying to get my Windows 7 box to ping the IPv6 local-link address on my Windows XP box. I have IPv6 enable on both machines. Both machines can ping the ::1 loop back and their own local-link IP's. Furthermore, the XP box can ping and receive and echo reply back from Windows 7 box. I ran the netsh interface ipv6> show neighbors command on both machines and they both see each other.

I have even ran a wireshark capture on both machines and I can see the echo request get to the XP machine, but no echo reply back gets back to the Windows 7 box. At first I noticed the hop limit was set to 0 on the Windows 7 box so I changed it to 128 like the XP box. I still had the problem. I then looked at the ICMPv6 packets and noticed a subtle difference in the ID field (see seciton 4.1 of RFC4443). The ID or Identifier field is set to ID: 0x0001 in the Window 7 echo requests and ID: 0x0000 in the XP echo request which get a reply.

I have also tried to see if it was a firewall issue, by turning off the firewalls on both computers which didn't work. Furthermore, I know the XP box is getting the echo requests (as seen in my wire shark capture).



I am at a loss now. Anyone have any ideas??

IPv6 isn't required in order to share with an XP machine from a Windows 7 machine. It's only used on the LAN and it's only required if you are using a Homegroup network. Homegroups is not made to work with a mixed Op system network.

Thanks for the response.

Actually I am not trying to have the XP box join the Homegroup. I just am at a loss as to why I can't ping the the local-link IPv6 address from my Windows 7 box to my XP box. It is just one of those problems that isn't really a big deal in the grand scheme of things, just something I want to figure out for the principle of it. I've just been messing around with IPv6 for the last couple of days, and just can't figure this one out. Unfortunately, I haven't upgraded my IOS on my router to IPv6 so I can't try pinging my router from the Window7 box or see if my Windows 7 RS multicasts (ff02::2) get responded by my router. That will be my next step

Some very old routers don't support IPv6 but that problem does'nt come up very often. Using A/V software and third party firewalls can also block access or prevent the ping from working correctly.

You should be able to see if both machines can access the IPv6 interface by doing an ipconfig /all on both machines and compairing the results. The physical IPv6 address under the torredo tunneling Pseudo-Interface should be the same. And the first part of the IPv6 address should be similar.

The link below shows you how to ping Ipv6 addresses but I'm not sure if it's possible to do so on the LAN. Never had a reason to ping an IPv6 address either because it usually just works although you can ping a special WAN Google IPv6 address that is set up for testing purposes only.

http://www.cyberciti.biz/faq/howto-t...ping6-command/

Ok thanks I'll check it out