Understanding the dual TCP/IP stack in Windows 8
A number of years ago, it was projected that the world would run out
of IPv4 addresses because there were so few. IPv4 provides computers
with a 32-bit network address. Therefore, there are just fewer than 4.3
billion possible IP
addresses with IPv4. Even though that sounds like a large number, there
is a lot of waste in the system and, in the early years of IPv4, there
was a lot of inefficiency in how addresses were distributed. Because
there was a perception that 4.3 billion was plenty of IP addresses,
some organizations were given far more IP addresses than they needed.
Between the waste in the system and the rapid increase in the number
of network-connected devices, 4.3 billion addresses are far from
sufficient. In response, the IETF created a new version of the Internet
Protocol. Today, that protocol is known as IPv6 and, although it’s
still in the process of worldwide deployment in many places, over time
it’s expected to supplant much of the use of IPv4.
Windows 8 includes full support for both IPv4 and IPv6, although at present you will rarely need to touch the IPv6 settings.
That said, you should understand at least the basics of IPv6 because
it’s enabled by default on Windows 8, and at times some services will
use it.
Whereas IPv4 provides 32-bit IP addresses, IPv6 provides 128-bit
addresses, with each address represented in eight 16-bit blocks. For
example, here’s the IP address used by the networking
adapter in the system used throughout this article:
fe80:0:0:0:7860:1f99:c25a:c329. As you can see, it looks radically
different from an IPv4 address. Further, the address as presented isn’t
what is actually displayed in the sample computer. Windows 8 displays
the address as fe80::7860:1f99:c25a:c329. Note the double colon between
the first and second parts of the address. This is the way IPv6
indicates that certain sections of the address are just zero. To make
it easier to read, the zeroed sections are omitted and a double colon
is put in their place.
In most organizations today, you won’t need to work with the IPv6 settings
manually, but the day is coming when IPv4 will be phased out, so make
sure you at least understand how to change your IPv6 settings.
Here’s how you change your IPv6 settings:
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Open Network And Sharing Center and tap or click Change Adapter Settings. -
When the list of network adapters appears, double-tap or right-click
the appropriate adapter and, from the shortcut menu, choose Properties. -
Under This Connection Uses The Following Items, choose Internet Protocol Version 6 (TCP/IPv6). -
Click the Properties button to open a Properties dialog box similar to the one in Figure 12. This system is currently configured to obtain an IP address from a DHCP server.
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Provide appropriate configuration settings and tap or click OK.
Configuring name resolution
You’ve already learned how to add DNS server entries to a network adapter’s configuration. There are additional name
resolution options that you might want to consider using on your
computers. Note that some of these name resolution options can be
configured on a DHCP server so that you don’t have to configure every
computer manually.
To change advanced name resolution properties for a network adapter, complete the following steps:
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Open Network And Sharing Center and tap or click Change Adapter Settings. -
When the list of network adapters appears, press and hold or
right-click the appropriate adapter and, from the shortcut menu, choose
the Properties option. -
Double-tap or double-click either Internet Protocol Version 4 (IPv4)
or Internet Protocol Version 6 (IPv6), depending on which version of
TCP/IP you want to configure. -
When the Internet Protocol properties page appears, tap or click the Advanced button and choose the DNS tab, shown in Figure 13.
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Make the configuration changes with the following options, and then tap or click OK.
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DNS Server Addresses, In Order Of Use In Figure 13,
note that this box contains a single entry. This computer has just one
DNS server IP address configured. You can add a second DNS server
address on the TCP/IP configuration page. However, you’re not limited
to just two DNS servers. By using this screen, you can add more DNS
servers. The more DNS servers you have available, the less likely it is
that the client will be left without a DNS server due to DNS failures.
The order here is important; Windows 8 uses the DNS servers in the
order that they are listed. Use the up and down arrows to change the
order of the listed DNS servers. -
Append Primary And Connection Specific DNS Suffixes If you’re using DNS, you’re also using a domain name
such as contoso.com as part of your computer naming convention. Suppose
this computer is attempting to reach a computer named
fileserver.contoso.com on the network. When this option is enabled,
Windows will automatically append the .contoso.com name to the end of network names, thus creating a fully qualified domain name that DNS can use. -
Append Parent Suffixes Of The Primary DNS Suffix
In larger organizations, DNS is broken down into smaller units. For
example, Contoso might have sales.contoso.com and
marketing.contoso.com. In that case, this computer name would be win8.sales.contoso.com. When you select the check box next to this option, Windows searches all the way up the name
resolution hierarchy looking for resources that match what you’re
looking for. As a result, if you attempt to access a resource named
fileserver and you don’t put the .contoso.com on the end, Windows will
look for resources named fileserver.sales.contoso.com and
fileserver.contoso.com. -
Append These DNS Suffixes (In Order)
If you have other names you want Windows to search for resources, you
can add those here. Windows searches these resources in the order in
which they appear on the list. Use the up and down arrows to change the
order of the DNS suffixes. -
DNS Suffix For This Connection Use this box to override any DNS suffix that has already been assigned to this computer. -
Register This Connection’s Addresses In DNS
This option uses a technology called Dynamic DNS, which allows the
desktop computer to update its own DNS record on your organization’s
DNS servers. If the computer’s IP address changes, the computer will
update DNS proactively so that an administrator doesn’t have to
remember to do it. -
Use This Connection’s DNS Suffix In DNS Registration By selecting this check box, you instruct Windows to update the DNS zone for the parent connection.
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