A small wired network may consist of an 8 or 5 port network switch which connects all computers together, and one Windows 7 machine running ICS bridging the network and the Internet connection through the ISP cable or dial-up modem as shown below. Internal computers can obtain their IPv4 configuration from the ICS machine while the ICS machine get its configuration from the modem which in turn is configured by the ISP. Some ISPs may provide you with a combined modem and router where you may omit the ICS computer as this role will be provided by the modem/router device.
The standard command-line tools we find in Windows 7 have full IPv6 functionality. Tools like Ping, Ipconfig, Pathping, Tracert, Netstat, and Route all support IPv6. Then we find tools specific to IPv6 which are provided in the Netsh command structure. But before we go for some troubleshooting tips, let’s check some mechanisms such as, IPv6 address resolution and configuration.
IPv6 uses 128 bits as opposed to 32 bits of an IPv4 address and this results in a new address space of 2pow128 that is, over 4 billion of available addresses. IPv6 allows for multiple levels of subnetting. The enormous address space created by the 128 bit format give us the option of allocating more than one IPv6 address to a host, with each address serving a specific purpose. In IPv6 we find addresses that are equivalent to IPv4 types and others that are unique to IPv6.
As you might be aware that we are running out of IPv4 Public addresses and that’s coming soon! Check some stats here - However, this does not mean the end of the IPv4 Internet as most service providers may still have quite a number of addresses while they can reclaim back unused ones. However, moving on to IPv6 has big advantages and this article deals briefly with the advantages that IPv6 has over IPv4.
IPv6 provides a set of compatibility addresses that help users migrate from IPv4 to IPv6 and these are IPv4-compatible, IPv4-mapped, 6to4 and Teredo addresses.
An IPv4-compatible address consists of an initial colon-hexadecimal notation and an ending dotted decimal notation as we find in IPv4. For example, 0:0:0:0:0:0:w.x.y.z or ::w.x.y.z, the last four octets represent an IPv4 address. IPv4-compatible addresses are used by hosts that are communicating with IPv6 over an IPv4 infrastructure. When an IPv4-compatible address is used as an IPv6 destination, the IPv6 traffic is automatically encapsulated with an IPv4 header.
You can view the IP configuration of your computer by using either the command-line tools Ipconfig or Netsh, or by using the Network and Sharing Center. The command-line tools display your computers’ network adapters IP settings including IPv4 and IPv6 addresses, subnet masks and the default gateway.
An IP address identifies a computer in a network and hence, each computer must have a unique address within the same network. Private IP addresses are used for internal networks while public addresses are used for the Internet. Since there are not enough public IP addresses to be allocated for every internal device, we use private addresses internally and use NAT to translate these addresses to a public address. An organization or individual that needs Internet access is allocated one or more public IP addresses through various agencies worldwide that are responsible for the distribution of public IP addresses.