So in my understanding of IPV6, you get a link local address via stateless autoconfiguration. This address is in the FE80 range and is for communicating with hosts on your local link. I have a copy of Vista on a virtual machine, and an internal network with a router serving DHCP. Its a Trendnet, and doesn't support IPV6. My question is, how did I receive a global IP address of 2001: ......Its under the "Tunnel adapter local area connection 7" area of the ipconfig output. I thought you only could receive a global range IP address from a router on your network that supports IPV6. Did I receive this address from my ISP? It's funny, this is a test setup at home. At work I have another Vista computer that does not have a global address entry. There are no routers or dhcp servers that are configured for IPV6 there either. What's the difference? And what is the "tunnel adapter local area connection 7"? Does this have to do with IPSec tunnel mode? Mouthful I know, but that's why these forums rock.thanks!CCNA, A+, N+

Hi, Thank you for your post. I know that you received an IP Address 2001: ...... and you want to know where it comes. Based on my research, this should be related to the ISATAP and I would like to share the following information with you: ISATAP is an address assignment and host-to-host, host-to-router, and router-to-host automatic tunneling technology defined in RFC 4214 that provides unicast IPv6 connectivity between IPv6/IPv4 hosts across an IPv4 intranet. ISATAP hosts do not require any manual configuration, and they can create ISATAP addresses using standard IPv6 address autoconfiguration mechanisms. ISATAP addresses have one of the two following formats: 64-bitUnicastPrefix:0:5EFE:w.x.y.z (when w.x.y.z is a private IPv4 address assigned to the ISATAP host) 64-bitUnicastPrefix:200:5EFE:w.x.y.z (when w.x.y.z is a public IPv4 address assigned to the ISATAP host) UnicastPrefix is any 64-bit unicast address prefix, including link-local, global, and unique local prefixes. Examples of ISATAP addresses are 2001:DB8::98CA:200:131.107.28.9 and 2001:DB8::98CA:0:10.91.211.17. Intra-site Automatic Tunnel Addressing Protocol Deployment Guide http://www.microsoft.com/downloads/details.aspx?FamilyID=0f3a8868-e337-43d1-b271-b8c8702344cd&displaylang=en Please check if your IPV6 Address 2001: ...... is ISATAP address with the information. If you are not sure, please run ipconfig /all and post the report to the thread and we will help you perform some further research. Hope this helps. Thanks. Nicholas Li - MSFT

Thanks I'll have to check, although I read the document you linked: " Without an ISATAP router, an ISATAP host will only use link-local ISATAP addresses" I don't have an ISATAP router, and therefore would not be getting a global address prefix from anywhere. I don't think this is how I got a global prefix address. CCNA, A+, N+

Hi, Thank you for your update. At this time, please collect the following information for our further research: 1. Run ipconfig /all and post the report to the thread. 2. Please open Device Manager, and then click on the view tab and select the option Show hidden devices. Then check if the ISATAP network adapter appears under the Network adapters. Please also capture a screenshot on this. Capture a screenshot ============== 1) Press the Print Screen key (PrtScn) on your keyboard. 2) Click the "Start" menu, type "mspaint" in the Search Bar and Press Enter. 3) In the Paint program, click the "Edit" menu, click "Paste", click the "File" menu, and click "Save". 4) The "Save As" dialogue box will appear. Type a file name in the "File name:" box, for example: "screenshot". 5) Make sure "JPEG (*.JPG;*.JPEG;*.JPE;*.JFIF)" is selected in the "Save as type" box, click Desktop on the left pane and then click "Save". Please use Windows Live SkyDrive (http://www.skydrive.live.com/) to upload the files and share the URLs with me. Thank you for your efforts. Nicholas Li - MSFT

Yeah there is an isatap network adapter under ipconfig/all but thats not the one that has the 2001. The 2001 is under pseudo tunnel adapter. Does anyone know? Also, under Network Connection properties, tcp/ip4 and tcp/ip6 are both installed, the ip6 address is set to be obtained automatically. I wonder where it is getting it from.CCNA, A+, N+

I think I found the answer Here is an excerpt from http://technet.microsoft.com/en-us/network/cc917483.aspx "The combination of IPv6, Teredo, and a host-based, stateful, IPv6 firewall does not affect the packet filtering function of the NAT for IPv4-based traffic and does not make your Windows-based computer more susceptible to attacks by malicious users and programs that use IPv6 traffic, rather than IPv4 traffic. When starting, a Windows-based computer using Teredo sends some Teredo traffic to automatically configure a global Teredo IPv6 address. However, no unsolicited, incoming, IPv6 traffic is allowed unless it matches a configured host-based firewall exception." This is both interesting and confusing.CCNA, A+, N+