IPv6 for Microsoft Windows: Frequently Asked Questions

It is unfortunate that some organizations disable IPv6 on their computers running Windows 7, Windows Vista, Windows Server 2008 R2, or Windows Server 2008, where it is installed and enabled by default. Many disable IPv6-based on the assumption that they are not running any applications or services that use it. Others might disable it because of a misperception that having both IPv4 and IPv6 enabled effectively doubles their DNS and Web traffic. This is not true.

From Microsoft's perspective, IPv6 is a mandatory part of the Windows operating system and it is enabled and included in standard Windows service and application testing during the operating system development process. Because Windows was designed specifically with IPv6 present, Microsoft does not perform any testing to determine the effects of disabling IPv6. If IPv6 is disabled on Windows 7, Windows Vista, Windows Server 2008 R2, or Windows Server 2008, or later versions, some components will not function. Moreover, applications that you might not think are using IPv6—such as Remote Assistance, HomeGroup, DirectAccess, and Windows Mail—could be.

Therefore, Microsoft recommends that you leave IPv6 enabled, even if you do not have an IPv6-enabled network, either native or tunneled. By leaving IPv6 enabled, you do not disable IPv6-only applications and services (for example, HomeGroup in Windows 7 and DirectAccess in Windows 7 and Windows Server 2008 R2 are IPv6-only) and your hosts can take advantage of IPv6-enhanced connectivity.

The changes to IPv6 in Windows 8 and Windows Server 2012 are the following:

• Better Internet connectivity
• NAT64/DNS64
• Windows PowerShell

For detailed information, see IPv6 - Technology Overview.

The changes to IPv6 in Windows 7 and Windows Server 2008 R2 are the following:

• HomeGroup
• DirectAccess
• IP-HTTPS
• Group Policy settings for transition technologies

For detailed information, see Support for IPv6 in Windows Server 2008 R2 and Windows 7.

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

• Dual IP layer architecture
• Installed and enabled by default
• Graphical user interface (GUI)-based configuration
• Full support for IPsec
• Multicast Listener Discovery version 2 (MLDv2) support
• Link-local Multicast Name Resolution (LLMNR) support
• Literal IPv6 addresses in Uniform Resource Locators (URLs)
• Support for ipv6-literal.net names
• IPv6 over the Point-to-Point Protocol (PPP)
• Dynamic Host Configuration for IPv6 (DHCPv6) support
• Random interface IDs
  
  

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:

• In the Network Connections folder, obtain properties on all of your connections and adapters and clear the check box next to the Internet Protocol Version 6 (TCP/IPv6) component in the list under This connection uses the following items.
  
  This method disables IPv6 on your LAN interfaces and connections, but does not disable IPv6 on tunnel interfaces or the IPv6 loopback interface.
• Add the following registry value (DWORD type) set to 0xFF:
  
  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\DisabledComponents
  
  This method disables IPv6 on all your LAN interfaces, connections, and tunnel interfaces but does not disable the IPv6 loopback interface. You must restart the computer for this registry value to take effect.

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.

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

1. Log on to the computer with a user account that has privileges to change network configuration.
2. Click Start, click Control Panel, and then double-click Network Connections.
3. Right-click any local area connection, and then click Properties.
4. Click Install.
5. In the Select Network Component Type dialog box, click Protocol, and then click Add.
6. In the Select Network Protocol dialog box, click Microsoft TCP/IP version 6, and then click OK.
7. Click Close to save changes to your network connection.
   
   

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:

1. Log on to the computer with a user account that has privileges to change network configuration.
2. Click Start, click Control Panel, and then double-click Network Connections.
3. Right-click any local area connection, and then click Properties.
4. Click Install.
5. In the Select Network Component Type dialog box, click Protocol, and then click Add.
6. In the Select Network Protocol dialog box, click Microsoft TCP/IP version 6, and then click OK.
7. Click Close to save changes to your network connection.
   
   

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:

1. Log on to the computer with a user account that has privileges to change network configuration.
2. Click Start, click Control Panel, and then double-click Network Connections.
3. Right-click any local area connection, and then click Properties.
4. Click Install.
5. In the Select Network Component Type dialog box, click Protocol, and then click Add.
6. In the Select Network Protocol dialog box, click Microsoft IPv6 Developer Edition, and then click OK.
7. Click Close to save changes to your network connection.
   
   

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:

1. Log on to the computer running Windows XP with a user account that has privileges to change network configuration.
2. Open a command prompt. From the Windows XP desktop, click Start, point to Programs, point to Accessories, and then click Command Prompt.
3. At the command prompt, type ipv6 install.
   
   

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

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

1. Log on to the computer with a user account that has privileges to change network configuration.
2. Click Start, click Control Panel, and then double-click Network Connections.
3. Right-click any local area connection, and then click Properties.
4. Click Microsoft TCP/IP version 6 (for Windows XP with SP2 or later or Windows Server 2003) or Microsoft IPv6 Developer Edition (for Windows XP with SP1), and then click Uninstall.
5. When prompted to confirm the removal of the Microsoft IPv6 Developer Edition or Microsoft TCP/IP version 6 protocol, click OK.
   
   

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:

1. Log on to the computer with a user account that has local administrator privileges.
2. From the Windows XP desktop, click Start, point to Programs, point to Accessories, and then click Command Prompt.
3. At the command prompt, type ipv6 uninstall.
   
   

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:

• In the Network Connections folder, obtain properties on all of your connections and adapters and clear the check box next to the Internet Protocol version 6 (TCP/IPv6) component in the list under This connection uses the following items.
  
  This method disables IPv6 on your LAN interfaces and connections, but does not disable IPv6 on tunnel interfaces or the IPv6 loopback interface.
• Add the following registry value (DWORD type) set to 0xFF:
  
  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\DisabledComponents
  
  This method disables IPv6 on all your LAN interfaces, connections, and tunnel interfaces but does not disable the IPv6 loopback interface. You must restart the computer for this registry value to take effect.
  
  

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.

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%4v 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

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 three types of unicast IPv6 addresses.

• Global addresses are equivalent to public IPv4 addresses and are used on the IPv6 Internet.
• Link-local addresses are equivalent to IPv4-based Automatic Private IP Addressing (APIPA) addresses used in current Microsoft operating systems and are used on a link.
• Unique local addresses (also known as local addresses) provide addresses that are private, but unique to an organization.
  
  

Link-local addresses are automatically configured for each interface. Global and unique 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.

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:

• Interface index 1 is a pseudo-interface that is used for loopback (named the Loopback Pseudo-Interface).
• Interface index 2 is a pseudo-interface that is used for the Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) IPv6 transition technology (named the Automatic Tunneling Pseudo-Interface).
• Interface index 3 is a pseudo-interface that is used for 6to4 tunneling (named the 6to4 Tunneling Pseudo-Interface).
• Other interfaces are numbered sequentially in the order in which they are created. This order varies among computers.
  
  

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.

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

1. In the DNS snap-in, right-click Reverse Lookup Zones and then click New Zone.
2. On the Welcome to the New Zone page for the New Zone Wizard, click Next.
3. On the Zone Type page, click the appropriate zone type, and then click Next.
4. On the Active Directory Zone Replication Scope page, click the appropriate zone replication behavior, and then click Next.
5. On the Reverse Lookup Zone Name page, click Reverse lookup zone name.
6. Type the IPv6 reverse lookup zone name in the ip6.arpa domain using reverse nibble notation, and then click Next.
   
   For example, for the IPv6 reverse lookup zone for the 2001:db8:0:39fa::/64 prefix, the IPv6 reverse lookup zone name is a.f.9.3.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa.
7. On the Dynamic Update page, click the appropriate behavior for dynamic updates, and then click Next.
8. On the Completing the New Zone Wizard page, click Finish.

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:

1. In the list under Reverse Lookup Zones, right-click the appropriate IPv6 reverse lookup zone, and then click New Pointer (PRT).
2. In Host IP number, type the interface ID of the IPv6 address in reverse nibble notation for the host.
   
   For example, for the interface ID ::2c08:3fac:9db:67f9, the Host IP number is 9.f.7.6.b.d.9.0.c.a.f.3.8.0.c.2.
3. In Host name, type the fully qualified domain name for the host.
4. Click OK.

Yes. The IPv6 protocol for Windows 8, Windows Server 2012, Windows 7, Windows Server 2008 R2, 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 Authentication Header (AH) and Encapsulating Security Payload (ESP) are supported for both transport and tunnel modes. However, ESP for the IPv6 protocol for Windows does not support data encryption.
• IPsec in the IPv6 protocol for Windows does not support the use of Internet Key Exchange (IKE) to negotiate security associations (SAs). IPsec policies, SAs, and the keys to calculate the Message Digest 5 (MD5) or Secure Hash Algorithm 1 (SHA-1) keyed hash for AH or ESP must be manually configured.
• IPsec for IPv6 traffic is completely independent from IPsec for IPv4 traffic. IPv6 IPsec security policies are not managed with the IP Security Policies snap-in. IPsec policies and SAs for the IPv6 protocol for Windows must be manually configured with the Ipsec6.exe tool. For more information and an example, see the topic titled "Using IPsec between two local link hosts" in Windows Server 2003 or Windows XP help.

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

• The DNS client supports the querying, processing, and dynamic registration of IPv6 host resource records, also known as AAAA (quad-A) records. For Windows 8, Windows Server 2012, Windows 7, Windows Server 2008 R2, Windows Vista, and Windows Server 2008, DNS messages can be exchanged over either IPv4 or IPv6. For Windows XP and Windows Server 2003, DNS messages can be exchanged only over IPv4. The Windows DNS client automatically configures the DNS server addresses of FEC0:0:0:FFFF::1, FEC0:0:0:FFFF::2, and FEC0:0:0:FFFF::3. You can also configure additional IPv6 addresses of IPv6-capable DNS servers using the netsh interface ipv6 add dns command.
• Even though IPv6 for Windows XP and Windows Server 2003 configures these DNS server addresses and supports the netsh interface ipv6 add dns command, DNS messages are only sent over IPv4. The DNS Server service in Windows Server 2008 R2, Windows Server 2008, and Windows Server 2003 supports the storage, querying, and dynamic registration of IPv6 host resource records. DNS messages can be exchanged over either IPv4 or IPv6. To enable the DNS Server service in Windows Server 2003 to use DNS over IPv6, use the dnscmd /config /EnableIPv6 1 command, and then restart the DNS Server service.

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

Windows 8, Windows Server 2012, Windows 7, and Windows Server 2008 R2 include full support for operation over IPv6 in all of its included networking applications and services.

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:

• IPv6-enabled versions of the Ipconfig, Ping, Tracert, Pathping, Netstat, and Route commands
• File and print sharing over IPv6
• IPv6-enabled Microsoft Internet Explorer and the Internet Information Services (IIS) Web service (the use of literal addresses are not supported by Wininet.dll)
• IPv6-enabled versions of the Telnet client (Telnet.exe), the Telnet server (Tlntsvr.exe), the File Transfer Protocol (FTP) client (Ftp.exe), and Windows Media Services
• IPv6 support for Windows Sockets, Remote Procedure Call (RPC), Internet Protocol Helper (IPHelper), Distributed Common Object Model (DCOM), and Win32 Internet Extensions (WinInet) APIs
• Network Monitor IPv6 header parsing support
  
  

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.

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

Windows XP includes the following tools that are not provided in Windows Server 2003:

• Ipv6.exe: Used for configuring the IPv6 protocol. The recommended method to configure IPv6 for Windows XP with SP2 and Windows XP with SP1 is by using commands in the netsh interface ipv6 context.
• Ping6.exe: The recommended tool to use for Windows XP with SP2 and Windows XP with SP1 is the IPv6-enabled version of the Ping.exe tool.
• Tracert6.exe: The recommended tool to use for Windows XP with SP2 and Windows XP with SP1 is the IPv6-enabled version of the Tracert.exe tool.
  
  

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

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:

1. Click Start, point to Settings, click Control Panel, and then double-click Add/Remove Programs.
2. In Add/Remove Programs, click Add/Remove Windows Components.
3. In the Windows Components wizard, select Management and Monitoring Tools, and then click Details.
4. In the Management and Monitoring Tools window, select the Network Monitor Tools check box, and then click OK.
5. If you are prompted for additional files, insert your Windows Server 2003 compact disc, or type a path to the location of the files on the network.

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

• Microsoft Platform Software Development Kit (SDK), January 2000 or later (available from the MSDN Web site).
• Microsoft Visual C++ version 6.0 or later.
• A computer running Windows 7, Windows Server 2008 R2, Windows Vista, Windows Server 2008, Windows Server 2003, or Windows XP with SP1 or later, with IPv6 installed.
  
  

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.