Configure IPv6 Windows 7
Since the introduction of IPv4 the Internet has slowly run out of 32-bit address spaces and that is why IPv6 is installed by default in Windows 7. There is no need to enable IPv6 on Windows 7 as IPv4 and IPv6 -which uses a 128-bit addressing scheme- are installed by default. Enable IPv6 Windows 7 Benefits:
- Efficient Hierarchical Addressing – useful for ISPs
- More Simple Routing Tables – Makes backbone routers easier to configure
- Stateful and Stateless Address Configuration – When no DHCP server is available (stateless) automatic configuration of the network is possible based on the addresses present in the available routers
- Improved Security – Ipv6 requires IPSec support making it more secure than IPv4
- Support for Link-Local Multicast Name Resolution (LNMR) – Ipv6 clients on a single subnet no longer require a DNS server for name resolution. Enabled by default in Windows Vista and Windows 7
- Improved Quality of Service (QoS) Support
- Extensibility – extension headers can be added to the IPv6 header enabling new features in future
Private IPv4 Addresses
- Private Class A 10.0.0.0 – 10.255.255.255
- Private Class B 172.16.0.0 – 172.31.255.255
- Private Class C 192.168.0.0 – 192.168.255.255
You use the Network and Sharing Center in Windows 7 to configure your network connection which will usually default be set to use DHCP.
If you are using more than one network like work and home you can enter an additional configuration to be used in the Alternate Configuration tab of the TCP/IP settings dialogue box.
Your primary network connection has to set to obtain an IP address automatically from DHCP to be able to view this tab.
The Advanced button allows you to specify multiple IP addresses for when you are hosting different websites for example. Bear in mind that you cannot configure more than one address if you are using DHCP.
The lower portion of the DNS tab lets you append DNS suffixes like for example home.local. What that means is that if a user tries to make a connection by just typing printer, home.local will automatically be added so that the query will look like printer.home.local.
When there is no DHCP server present the Automatic Private Internet Protocol Addressing (APIPA) provides an alternative way of distributing addresses to the network. APIPA addresses are in the 169.254.0.1 to 169.254.255.254 range with a subnet mask of 255.255.0.0.
Windows 7 and IPv6 – Configure IPv6
Unlike IPv4 addresses, IPv6 Windows 7 uses a 128-bit addressing scheme which consists of 16-bit blocks. Each block is represented by a four digit hexadecimal number separated by a colon and is referred to as colon-hexadecimal notation. In an IPv6 configuration any leading zeros can be replaced by a double colon.
Different Types of IPpv6 for Windows 7 Addresses – http://technet.microsoft.com/en-us/library/cc759208%28WS.10%29.aspx
- Unicast – packets are addressed to a single network interface
Global Addresses – equivalent to IPv4 public addresses and typically starts with a “2”
Link-local Addresses – equivalent to IPv4 APIPA addresses and typically starts with “fe8”
Site-local Addresses – equivalent to IPv4 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 and starts with “fec0”
- Special Addresses – unspecified address 0:0:0:0:0:0:0:0 or :: equivalent to IPv4 0.0.0.0 and loopback address 0:0:0:0:0:0:0:1 or ::1 equivalent to IPv4 127.0.0.1
- Multicast – packets are addressed to multiple interfaces and address starts with “ff”
- Anycast – A multicast address is used for one-to-many communication, with delivery to multiple interfaces. An anycast address is used for one-to-one-of-many communication, with delivery to a single interface. Only assigned to routers
Just like IPv4 private addresses Windows 7 IPv6 private addresses are not accessible from the internet. You can also not access Site-local IPv6 Addresses from the internet.
- Represented by 0:0:0:0:0:0:w.x.y.z or ::w.x.y.z where w.x.y.z is the IPv4 address
- Used by dual stack nodes communicating with IPv6 over an IPv4 network
- Represented by ::ffff:w.x.y.z
- Used to map IPv4 devices not compatible with IPv6 to IPv6 devices
- Teredo allows for connectivity between IPv4/IPv6 nodes across NAT interfaces
- A Teredo address starts with 2001; a 6to4 address starts with 2002
- Used by two nodes that are both running IPv4 and IPv6
- A 6to4 address enables IPv6 packets to be transmitted over an IPv4 network
IPv6 can be disabled but not removed from a Windows 7 computer.
IPv6 Connectivity Windows 7 Troubleshooting Steps
When troubleshooting connectivity problems one might start by pinging the localhost loopback address 127.0.0.1 to check that the computer’s TCP/IP stack is functioning. The Ping6 command-line tool is not supported in Windows 7.
- Ping localhost (127.0.0.1) IPv6 equivalent is ping ::1
- Check hardware is OK
- Run Ipconfig /all or netsh interface ipv6 show address if you want to just display the IPv6 statistics
- Ping localhost
- Ping computer address
- Ping default gateway
- Ping host outside the network to verify router connectivity
Command Line Tools
- Netsh interface ip delete arpcache
- Ipconfig /flushdns
Network Discovery is enabled by default on Windows 7 computers
How to Enable IPv6 in Windows 7 – IPv6 Troubleshooting – http://technet.microsoft.com/en-us/library/bb878005.aspx
Clear the neighbor cache on the computer before pinging by typing netsh interface ipv6 delete neighbors
Zone ID can be obtained by typing Ipconfig /all or netsh interface ipv6 show interface. Supposing the zone Id is 10 you would append %10 to the IPv6 address when pinging. Install iIPv6 Windows 7 is a useless query as the feature is installed by default in Windows 7.
Should you wish to disable IPv6 in Windows 7 you can do so by unchecking the enable IPv6 option on the Local Area Connection properties tab.