IPv6 for Microsoft Windows: Frequently Asked Questions

For a first look at IPv6 concepts, see Help and Support for Windows Vista, Windows Server 2008, Windows XP, or Windows Server 2003.

For an in-depth discussion of IPv6 concepts and protocols, see the Introduction to IPv6 white paper or the Introduction to IPv6 Webcast. For additional information about IPv6 in Microsoft Windows, see the Microsoft Windows IPv6 Web site.

See the Development and Deployment of IPv6: Good for Internet, Technology article.

Yes. You can access IPv6 online help through the table of contents, the index, or the full text search of Windows Vista, Windows Server 2008, or Windows XP Help and Support. IPv6 online help contains extensive information on IPv6 concepts, features, procedures, configurations, and troubleshooting.

To access IPv6 help content in Windows Vista, click Start, click Help and Support, type IPv6, and then press ENTER.

Windows Vista and Windows Server 2008 support an integrated IPv4 and IPv6 implementation known as the Next Generation TCP/IP stack. For more information, see Next Generation TCP/IP Stack in Windows Vista and Windows Server 2008.

Microsoft provides supported IPv6 implementations for Windows Server 2003, Windows XP with Service Pack 1 (SP1) or later, and Windows CE .NET 4.1 or later.

No. Microsoft has no plans to provide supported IPv6 protocol implementations for Windows 2000, Windows 98, and older versions of Windows.

The changes to IPv6 in Windows Vista and Windows Server 2008 are the following:

For detailed information, see Changes to IPv6 in Windows Vista and Windows Server 2008.

Unlike Windows XP and Windows Server 2003, IPv6 in Windows Vista and Windows Server 2008 cannot be uninstalled. However, you can disable IPv6 in Windows Vista and Windows Server 2008 by doing one of the following:

For additional information about the DisabledComponents registry value, see Configuring IPv6 with Windows Vista.

If you disable IPv6, you will not be able to use Windows Meeting Space or any application that relies on the Windows Peer-to-Peer Networking platform or the Teredo transition technology.

For a detailed answer, see Domain Name System Client Behavior in Windows Vista.

The IPv6 protocol for Windows Vista and Windows Server 2008 is installed and enabled by default. It appears as the Internet Protocol Version 6 (TCP/IP) component on the Configure tab when you obtain the properties of a connection or adapter in the Network Connections folder (available from the Network and Sharing Center).

To install the IPv6 protocol for Windows Server 2003, perform the following steps:

Alternately, from the Windows Server 2003 desktop, click Start, point to Programs, point to Accessories, and then click Command Prompt. At the command prompt, type netsh interface ipv6 install.

To use Remote Procedure Call (RPC) applications over IPv6, you must first restart the computer.

To install the IPv6 protocol for Windows XP with SP2 or later, do the following:

Alternately, from the Windows XP desktop, click Start, point to Programs, point to Accessories, and then click Command Prompt. At the command prompt, type netsh interface ipv6 install.

For the IPv6 protocol for Windows XP with SP1, do the following:

Alternately, from the Windows XP desktop, click Start, point to Programs, point to Accessories, and then click Command Prompt. At the command prompt, type netsh interface ipv6 install.

To install the IPv6 protocol for Windows XP with no service packs installed:

Regardless of the version of Windows XP, to use RPC applications over IPv6, you must first restart the computer.

The installation of the IPv6 Protocol for Windows XP with no service packs installed does not use the standard procedure for protocol installation in the Network Connections folder. Therefore, it is not visible as an installed protocol. To determine whether IPv6 is installed, type ipv6 if at a command prompt. If IPv6 is installed, you will see a display of your IPv6 interfaces and their configuration. Otherwise, the Ipv6.exe tool will indicate that IPv6 is not installed.

Despite the displayed name, the IPv6 protocol for Windows XP with SP1 is a production-capable and supported protocol in the same way as the IPv6 protocol for Windows XP with SP2 and Windows Server 2003. Microsoft developers were unable to change the name of the protocol in Windows XP SP1 due to the impact of the change for localized versions of Windows XP. In Windows XP with SP2, the name of the IPv6 protocol has been changed to "Microsoft TCP/IP version 6."

For the IPv6 protocol for Windows XP with SP1 or later or Windows Server 2003, do the following:

Alternately, from the Windows XP or Windows Server 2003 desktop, click Start, point to Programs, point to Accessories, and then click Command Prompt. At the command prompt, type netsh interface ipv6 uninstall.

To remove the IPv6 protocol for Windows XP with no service packs installed, do the following:

Unlike Windows XP and Windows Server 2003, IPv6 in Windows Vista and Windows Server 2008 cannot be uninstalled. However, you can disable IPv6 in Windows Vista and Windows Server 2008 by doing one of the following:

By default, IPv6 configures link-local IPv6 addresses for each IPv6 interface. Link-local addresses have the prefix FE80::/64. Additional global or unique local addresses might also be configured depending on whether you have routers that are sending Router Advertisement messages.

For Windows Vista, Windows Server 2008, Windows Server 2003, Windows XP with SP2, and Windows XP with SP1, you can use the ipconfig command to view your IPv6 addresses. Here is an example:

c:\>ipconfig

Windows IP Configuration

Ethernet adapter Ethernet: 


        Connection-specific DNS Suffix  . : wcoast.corp.example.com

        IP Address. . . . . . . . . . . . : 157.54.139.57

        Subnet Mask . . . . . . . . . . . : 255.255.252.0

        IP Address. . . . . . . . . . . . : 2001:db8:8311:f282:1460:5260:c9b1:fda6

        IP Address. . . . . . . . . . . . : 2001:db8:8311:f282:b973:4db8:97e2:e978

        IP Address. . . . . . . . . . . . : 2001:db8:8311:f282:200:39ff:fe0e:fc35

        IP Address. . . . . . . . . . . . : fec0::f282:200:39ff:fe0e:fc35%1

        IP Address. . . . . . . . . . . . : fe80::200:39ff:fe0e:fc35%4

        Default Gateway . . . . . . . . . : 157.54.136.1

                                            fe80::210:ffff:fed6:58c0%4

Tunnel adapter 6to4 Tunneling Pseudo-Interface: 

        Connection-specific DNS Suffix  . : wcoast.corp.example.com

        IP Address. . . . . . . . . . . . : 2002:9d3b:8b39::9d3b:8b39

        Default Gateway . . . . . . . . . : 

Tunnel adapter Automatic Tunneling Pseudo-Interface: 

        Connection-specific DNS Suffix  . : wcoast.corp.example.com

        IP Address. . . . . . . . . . . . : fec0::f70f:0:5efe:157.54.139.57%1

        IP Address. . . . . . . . . . . . : 2001:db8:8311:f70f:0:5efe:157.54.139.57

        IP Address. . . . . . . . . . . . : fe80::5efe:157.54.139.57%2

        Default Gateway . . . . . . . . . : fe80::5efe:157.56.253.8%2

For Windows Vista, Windows Server 2008, Windows Server 2003, Windows XP with SP2, and Windows XP with SP1, you can also use the netsh interface ipv6 show address command to view your IPv6 addresses. Here is an example:

Interface 4: Ethernet

Addr Type  DAD State  Valid Life Pref. Life Address

---------  ---------- ---------- ---------- -----------------------------------

Anonymous  Preferred      596758      78191 2001:db8:8311:f282:1460:5260:c9b1:fda6

Anonymous  Deprecated     510530          0 2001:db8:8311:f282:b973:4db8:97e2:e978

Public     Preferred     2591874     604674 2001:db8:8311:f282:200:39ff:fe0e:fc35

Public     Preferred     2591874     604674 fec0::f282:200:39ff:fe0e:fc35

Link       Preferred  4294967295 4294967295 fe80::200:39ff:fe0e:fc35

Interface 3: 6to4 Tunneling Pseudo-Interface

Addr Type  DAD State  Valid Life Pref. Life Address

---------  ---------- ---------- ---------- -----------------------------------

Other      Preferred  4294967295 4294967295 2002:9d3b:8b39::9d3b:8b39

Interface 2: Automatic Tunneling Pseudo-Interface

Addr Type  DAD State  Valid Life Pref. Life Address

---------  ---------- ---------- ---------- -----------------------------------

Public     Preferred     2591700     604500 fec0::f70f:0:5efe:157.54.139.57

Public     Preferred     2591700     604500 2001:db8:8311:f70f:0:5efe:157.54.139.57

Link       Preferred  4294967295 4294967295 fe80::5efe:157.54.139.57

Interface 1: Loopback Pseudo-Interface

Addr Type  DAD State  Valid Life Pref. Life Address

---------  ---------- ---------- ---------- -----------------------------------

Loopback   Preferred  4294967295 4294967295 ::1

Link       Preferred  4294967295 4294967295 fe80::1

For more information about IPv6 configuration, see Using Windows Tools to Obtain IPv6 Configuration Information.

There are four types of unicast IPv6 addresses.

Link-local addresses are automatically configured for each interface. Global, site-local, and local addresses are automatically configured based on the receipt of a Router Advertisement (RA) message that contains Prefix Information options. IPv6 routers send RA messages.

For more information about IPv6 address autoconfiguration, see the Introduction to IPv6 white paper.

The link-local address is a combination of the link local prefix FE80::/64 and a 64-bit IPv6 interface identifier (ID).

In Windows XP and Windows Server 2003, the IPv6 interface ID is derived from the Extended Unique Identifier (EUI)-64 address. The EUI-64 address is either assigned to a network adapter or derived from the 48-bit media access control (MAC) address of a network adapter. To create the EUI-64 address from the 48-bit (6-byte) Ethernet MAC address, the hex digits 0xff-fe are inserted between the third and fourth bytes of the Ethernet MAC address.

For example, for the MAC address 00-60-08-52-f9-d8, the hex digits 0xff-fe are inserted between 0x08 (the third byte) and 0x52 (the fourth byte) of the MAC address, forming the EUI-64 address 00-60-08-ff-fe-52-f9-d8.

To obtain an IPv6 interface identifier from an EUI-64 address, the Universal/Local bit, the second low-order bit of the first byte of the EUI-64 address, is complemented (if it is a 1, it is turned to 0, and if it is a 0, it is turned to 1). For example, for the EUI-64 address of 00-60-08-ff-fe-52-f9-d8, the second low-order bit of 0x00 is 0, which, when complemented, becomes a 1. The result is that for the first byte, 0x00 becomes 0x02. Therefore, the IPv6 interface identifier corresponding to the EUI-64 address of 00-60-08-ff-fe-52-f9-d8 (corresponding to the Ethernet media access control address of 00-60-08-52-f9-d8) is 02-60-08-ff-fe-52-f9-d8.

Because the link-local address is the combination of the prefix FE80::/64 and the 64-bit interface identifier expressed in IPv6 colon-hexadecimal notation, the link-local address of this example node, with the prefix FE80::/64 and the interface identifier 02-60-08-ff-fe-52-f9-d8, is fe80::260:8ff:fe52:f9d8.

In Windows Vista and Windows Server 2008, the interface ID by default is randomly derived, rather than based on the EUI-64 address. You can disable random interface IDs with the netsh interface ipv6 set global randomizeidentifiers=disabled command or enable random interface IDs with the netsh interface ipv6 set global randomizeidentifiers=enabled command.

When you type the netsh interface ipv6 show interface command for Windows Server 2003, Windows XP with SP2, or Windows XP with SP1, you see a list of all of the IPv6 interfaces:

With the exception of the Loopback Pseudo-Interface, your interfaces might be different. The link-local address of a LAN interface uses the IPv6 interface identifier derived from the Ethernet MAC address, as described in the "How is the link-local address derived?" question in this article.

IPv6 in Windows XP and Windows Server 2003 uses the "Automatic Tunneling Pseudo-Interface" for encapsulating IPv6 packets with an IPv4 header so that they can be sent across an IPv4 network. By default, IPv6 configures a link-local Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) address on the Automatic Tunneling Pseudo-Interface. The link-local ISATAP address has the form fe80::200:5efe:w.x.y.xor fe80::5efe:w.x.y.x, in which w.x.y.x is an IPv4 address assigned to the computer.

For most hosts, you do not need to manually configure IPv6 addresses. In addition to auto-configuring link-local addresses for all Ethernet interfaces, the IPv6 protocol for Windows participates in router discovery to discover the presence of local IPv6 or ISATAP routers and autoconfigure additional IPv6 addresses. Router discovery requires a properly configured IPv6 router on your network segment or an ISATAP router.

Without an IPv6 or ISATAP router, you can manually configure additional IPv6 addresses on interfaces using the netsh interface ipv6 add address command on computers running Windows. This command allows you to specify the interface, the address, the preferred and valid lifetimes, and whether the address is unicast or anycast. Manually configured addresses must be reachable to communicate with other IPv6 nodes.

For more information and examples, see Manual Configuration for IPv6.

To enable IPv6 routing, you must use the netsh interface ipv6 set interface command to enable forwarding and advertising on the appropriate interfaces, and then use the netsh interface ipv6 add routes command to configure subnet prefixes to publish. To have an IPv6 router running Windows advertise itself as a default router, you must configure a default route and publish it.

For more information and examples, see Manual Configuration for IPv6.

Link-local and site-local addresses can be reused. Link-local addresses are reused on each link. Site-local addresses can be reused within each site of an organization. Because of this address reuse capability, link-local and site-local addresses are ambiguous. To specify which link on which the destination is located or within which site the destination is located, an additional identifier is needed. This additional identifier is a zone identifier (ID), also known as a scope ID, which identifies a connected portion of a network that has a specified scope.

The syntax specified in RFC 4007 for identifying the zone associated with a link-local or site-local address is Address%zone_ID in which Address is a link-local or site-local unicast IPv6 address and zone_ID is an integer value representing the zone. The values of the zone ID are defined relative to the sending host. Therefore, different hosts might determine different zone ID values for the same physical zone. For example, Host A might choose 3 to represent the zone of an attached link and host B might choose 4 to represent the same link.

The IPv6 protocol for Windows Server 2003 and Windows XP with SP1 or later includes an IPv6-capable Ping.exe tool. The new Ping sends ICMPv6 Echo Request messages to the specified destination and displays round-trip time statistics on the corresponding Echo Reply messages. To ping using an IPv6 address, the Ping.exe syntax is the following: ping IPv6Address [%ZoneID]

The ZoneID option specifies the scope or zone of the destination for the ICMPv6 Echo Request messages. For link-local addresses, the zone identifier (ID) is typically equal to the interface index, as displayed in the output of the netsh interface ipv6 show interface command. For site-local addresses, the zone ID is equal to the site number, as displayed in the output of the netsh interface ipv6 show interface level=verbose command. If multiple sites are not being used, a zone ID for site-local addresses is not required. You can also obtain the zone ID from the display of the Ipconfig command. The number after the "%" character in the display of an address indicates the zone ID. The zone ID is not needed when the destination is a global address.

For example, to send Echo Request messages to the link-local address FE80::260:97FF:FE02:6EA5 using zone ID 4 (the interface index of an installed Ethernet adapter), use the following command:

ping fe80::260:97ff:fe02:6ea5%4

Because the zone ID is locally defined, the zone ID of the sending host may not be the same as the zone ID of the destination host for the same zone. For example, for Host A and Host B connected the same link, Host A's zone ID for the link is 4 and Host B's zone ID for the link is 3. When Host A pings Host B, the zone ID used in the ping command is 4. When Host B pings Host A, the zone ID used in the ping command is 3.

No. There is no mechanism to indicate the zone ID for an IPv6 address in an entry in the Hosts file. Therefore, you should not have entries in the Hosts file for link-local addresses. You should use the Hosts file only for site-local addresses (if you are only using one site) or global addresses.

The Migrating IPv6.exe Commands to Netsh Commands Web page contains a list of the Ipv6.exe commands and their Netsh equivalents.

You can send IPv6 traffic over the IPv4 portion of the Internet by using the 6to4 or Teredo transition technologies. 6to4 is supported by all versions of Windows XP. Teredo is supported by Windows Server 2003 with Service Pack 1, Windows XP with SP2 or later, and Windows XP with SP1 and the Advanced Networking Pack for Windows XP. For more information about 6to4 and Teredo, see the IPv6 Transition Technologies white paper.

Without an IPv6 router, you can send traffic between two hosts on the same subnet (or link) using their link-local addresses.

To send IPv4-encapsulated IPv6 traffic between hosts on different subnets over an existing IPv4 routing infrastructure, you can use the Intra-Site Automatic Tunnel Addressing Protocol (ISATAP). For more information, see the IPv6 Transition Technologies white paper.

To reach the IPv6 Internet from behind a network address translator (NAT) using the Teredo client included with Windows, there must be an operational Teredo relay attached to the IPv4 and IPv6 Internets. At this time, Microsoft is not providing any operational Teredo relays for reachability to locations on the IPv6 Internet for Windows-based Teredo clients.

To create an IPv6 reverse lookup zone, do the following:

In the console tree, you should see the new zone listed.

IPv6-based Windows DNS clients do not register their IPv6 reverse lookup records with DNS dynamic update. To manually add an IPv6 pointer (PTR) record, do the following:

IPsec for the IPv6 protocol for Windows Vista and Windows Server 2008 has full support for IPsec.

IPsec for the IPv6 protocol for Windows Server 2003 and Windows XP is supported, with the following limitations:

The IPv6 protocol for Windows XP and Windows Server 2003 provides correspondent node support as described in version 13 of the Internet draft titled "Mobility Support in IPv6" (now RFC 3775). The IPv6 protocol for Windows does not provide support mobile node or home agent support. By default, the correspondent node functionality is disabled and binding updates are required to use the IPsec Authentication Header (AH) for authentication. To enable the correspondent node functionality, use the netsh interface ipv6 set mobility correspondentnode=enabled command.

The IPv6 protocol for Windows Vista and Windows Server 2008 does not support Mobile IPv6.

For more information about Mobile IPv6, see Introduction to Mobile IPv6.

The Mobile IPv6 Technology Preview was developed by Microsoft Research and supports full RFC 3775-compliant correspondent node, mobile node, and home agent functionality for computers running various versions of Windows. However, the Mobile IPv6 Technology Preview is not currently available. Microsoft will consider making a version of Mobile IPv6 available for use in the future if there is sufficient customer demand.

Windows Vista, Windows Server 2008, Windows XP with SP1 or later, and Windows Server 2003 include an IPv6-enabled version of the Ping.exe tool. When you ping a link-local address with the Ping.exe tools, you must include a zone identifier (ID), which specifies the interface over which the ICMPv6 Echo Request messages are sent. For link-local addresses, the zone ID is typically equal to the interface index, as displayed in the output of the netsh interface ipv6 show interface or command.

For site-local addresses, the zone ID is equal to the site number, as displayed in the output of the netsh interface ipv6 show interface level=verbose command. If multiple sites are not being used, a zone ID for site-local addresses is not required.

The zone ID is not needed when the destination is a global address.

For example, to send ICMPv6 Echo Request messages to the link-local address fe80::260:97ff:fe02:6ea5 using zone ID 4 (the interface index of an installed Ethernet adapter), use the following command:

ping fe80::260:97ff:fe02:6ea5%4

Yes. The IPv6 protocol for Windows supports DNS in the following ways:

For more information of IPv6 support in the DNS Server service of Windows Server 2008, see DNS Enhancements in Windows Server 2008.

The new Internet extensions DLL, Wininet.dll, enables Web browsers to access IPv6-enabled Web servers. For example, Wininet.dll is used by Microsoft Internet Explorer to make connections with a Web server to view Web pages. Internet Explorer uses IPv6 to download Web pages when the Domain Name System (DNS) query (or Hosts file) for the name of the Web server in the URL returns an IPv6 address. You can then connect to names that resolve only to IPv6. To verify that the DNS query returns IPv6 addresses, try to ping the Web server domain name using the Ping.exe tool.

URLs that use the format for literal IPv6 addresses described in RFC 3896 are not supported by the version of Internet Explorer provided with Windows Server 2003 or Windows XP. For applications other than Internet Explorer, connect using a literal IPv6 address.

Internet Explorer in Windows Vista and Windows Server 2008 supports URLs that use the format for literal IPv6 addresses, as described in RFC 3896.

Note: Internet Explorer cannot browse IPv6 Web sites if it is configured to use a proxy server. When Internet Explorer is configured to use a proxy server, all name resolution requests for Web sites are forwarded to the proxy server. Until the proxy server is IPv6-enabled, proxy-based requests for local or remote IPv6 Web pages are unsuccessful. For information about how to configure Internet Explorer to operate without the use of a proxy server, see Internet Explorer Help.

The DNS server does not support AAAA (IPv6 address) resource records and incorrectly responds with an authoritative response that returns NXDOMAIN or NAME_ERROR (Response Code, or RCODE, 3). For more information, see Microsoft Knowledge Base Article - 815768.

Windows Server 2008 includes full support for operation over IPv6 in all of its included networking applications and services, except for the File Transfer Protocol (FTP) Publishing service and the Simple Mail Transfer Protocol (SMTP) Server service in Internet Information Services (IIS). The SMTP feature of Microsoft Exchange Server 2007 with Service Pack 1 includes an IPv6-capable SMTP service. Windows Vista includes full support for operation over IPv6 in all of its included networking applications and services, except for the File Transfer Protocol (FTP) Publishing service in Internet Information Services (IIS).

Windows Server 2003 contains the following:

Windows XP does not include IPv6 support for file and printer sharing or the IPHelper or DCOM APIs.

The IPv6 protocol for Windows XP with no service packs installed was provided as a developer preview. The IPv6 protocol for Windows Server 2003, Windows XP with SP1, and Windows XP with SP2 is a production-capable and supported protocol.

All versions of Windows XP do not include IPv6 support for file and print sharing or the IPHelper and DCOM APIs.

All versions of Windows XP include the following tools that are not provided in Windows Server 2003:

Windows Server 2003 Service Pack 1 or later and Windows XP SP2 or later includes support for Teredo and the new Windows Firewall.

URLs that use the format for literal IPv6 addresses described in RFC 3896 are not supported by the Internet extensions DLL, Wininet.dll, provided with Windows XP and Windows Server 2003. Wininet.dll does support IPv6 to access Web services when name resolution for the name of the Web server in the URL returns an IPv6 address.

Internet Explorer and Wininet.dll in Windows Vista and Windows Server 2008 support URLs that use the format for literal IPv6 addresses, as described in RFC 3896.

Note: Internet Explorer cannot browse IPv6 Web sites if it is configured to use a proxy server. When Internet Explorer is configured to use a proxy server, all name resolution requests for Web sites are forwarded to the proxy server. Until the proxy server is IPv6-enabled, proxy-based requests for local or remote IPv6 Web pages are unsuccessful. For information about how to configure Internet Explorer to operate without the use of a proxy server, see Internet Explorer Help.

To capture IPv6 packets, use any software- or hardware-based protocol analyzer (also known as a network sniffer) that parses IPv6 headers. For example, you can use the version of Network Monitor included with Windows Server 2003 or Network Monitor 3.1 or later.

To install the version of Microsoft Network Monitor included with Windows Server 2003, do the following:

Changes to existing Sockets functions are documented in Request for Comments (RFC) 3493, "Basic Socket Interface Extensions for IPv6." For the details of Windows Sockets support in the IPv6 protocol for Windows Server, see the IPv6 Guide for Windows Sockets Applications.

For Winsock IPv6 application development, you will need the following:

The Windows Platform SDK includes a tool called Checkv4.exe. Checkv4.exe scans source code files to identify code that needs to be changed to support IPv6. Checkv4 displays the line number and a message recommending how the code should be changed. Here is an example of Checkv4.exe output:

test.c(35) : gethostbyname : use getaddrinfo instead

test.c(40) : gethostbyaddr : use getnameinfo instead

test.c(48) : SOCKADDR_IN : use SOCKADDR_STORAGE instead, or use

SOCKADDR_IN6 in addition for IPv6 support

test.c(57) : AF_INET : use AF_INET6 in addition for IPv6 support

test.c(89) : inet_addr : use WSAStringToAddress or getaddrinfo with

AI_NUMERICHOST instead

For more information, see Using the Checkv4.exe Utility.

For detailed information about modifying your applications to work over both IPv4 and IPv6, see the IPv6 Guide for Windows Sockets Applications.

This version of the IPv6 protocol for Windows features dynamic linking support that allows IPv6/IPv4 applications to still run on platforms that do not support IPv6. The dynamic linking support is enabled by default and contained in the file Wspiapi.h in the Platform SDK. You should not include this file in your project directly.

In future versions of Windows, you may choose to save space in your IPv6-enabled applications and eliminate additional OS support by having _WIN32_WINNT defined larger than 0x0500. For more information on the _WIN32_WINNT macro, consult your Platform SDK documentation.