Windows Server 2008 R2 Unleashed (67 page)

networks. The Teredo relay routes between Teredo clients and IPv6 hosts in the IPv6

network.

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.
Teredo host-specific relay—
This is an IPv6/IPv4 device that is connected to IPv6

and IPv4 networks. It can communicate with the IPv6 network, the IPv4 network,

and Teredo clients without a Teredo relay.

Figure 10.26 shows the components of Teredo.

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Teredo Relay

IPv6 Internet

IPv4 Internet

Windows Server 2008 R2

Teredo Host

Windows 7

Windows Server 2008 R2

IPv6 Host

IPv6 Host

Windows Server 2008 R2

Teredo Host-Specific Relay

NAT

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Windows 7

Teredo Client

FIGURE 10.26

Teredo network.

Windows Server 2008 R2, Windows Server 2008, Windows 7, and Windows Vista can all

operate as Teredo clients and Teredo host-specific relays.

The Windows Teredo clients send Router Solicitation messages to Teredo servers. These

responses to the router solicitation messages are used to build the Teredo address and what

type of NAT is in place.

NOTE

The command netsh interface ipv6 show teredo can be used to see how the

Teredo client configured itself.

Once the Teredo address has been determined, the Teredo client can then communicate

with Teredo clients. This is facilitated by the Teredo server, which brokers communications

How to Configure IPv6 on Windows Server 2008 R2

311

between the two Teredo clients during the initial start of communications. Following the

initial setup of communications, the two Teredo clients communicate directly.

NAT-PT Devices

Internally, IPv6 devices can use Network Address Translation-Protocol Translation (NAT-PT)

devices, which can be used to provide access to IPv4 resources. Resources that don’t support

IPv6 natively can be accessed through the use of a Network Address Translation-Protocol

Translation (NAT-PT) device. Microsoft Windows Server 2008 R2 does not currently include

that capability, so a third-party device would be needed for this functionality.

NOTE

NAT-PT is covered in IETF RFC-2766 (http://tools.ietf.org/html/rfc2766), but was

reclassified from a Proposed Standard to Historic due to issues with the standard.

RFC4966 (http://tools.ietf.org/html/rfc4966) contains the details of these issues.

These include difficulty with integrity mechanisms, inability to redirect protocols that

lack demultiplexing capabilities, premature state timeouts, loss of information due to

IPv4 and IPv6 header incompatibilities, packet fragmentation issues, and an inability to

handle multicast traffic. NAT-PT devices are only recommended as a stop-gap measure

due to these issues.

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As long as all Intranet resources that IPv6 clients need to reach support IPv6, then there

should be no need for NAT-PT devices.

How to Configure IPv6 on Windows Server 2008 R2

Many of the tasks for configuring IPv6 are exactly the same as those for IPv4 addresses,

albeit with longer addresses to type. This includes manually setting IP addressing, creating

DHCP scopes, and creating DNS host records. The steps in this section walk through some

of the administrator tasks for configuring IPv6 on Windows Server 2008 R2.

Manually Setting the IPv6 Address

On many occasions, it is necessary to set the IP addresses manually. This is normally the

case for servers, routers, and other devices that have static IP addresses.

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To set the IPv6 addressing of a Windows Server 2008 R2 server, execute the following steps:

1. Launch Server Manager.

2. Click on View Network Connections from the options in the left pane of the window.

3. Right-click on the desired Local Area Connection, and select Properties.

4. Click Internet Protocol Version 6 (TCP/IPv6), and select Properties. If the item is not

enabled, check the box first.

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5. Click the Use the Following IPv6 Address option button.

6. In the IPv6 Address field, type in Fc00:1234:5678:9abc::2, and then press Tab. Notice

that the Subnet Prefix Length field auto-populates with “64.” Leave that in place and

press Tab to move to the Default Gateway input field.

7. Enter Fc00:1234:5678:9abc::1 for the default gateway.

8. Press Tab again to move to the Use the Following DNS Server Address field. Then

press Tab to move to the Preferred DNS Server input field. For this example, use the

IPv6 address for this server. In the Preferred DNS Server field, type in the sample

IPv6 address Fc00:1234:5678:9abc::2 and leave the Alternate DNS Server field blank.

The settings should match those shown in Figure 10.27.

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FIGURE 10.27

IPv6 settings.

9. Click OK to close the IPv6 Properties window. Click Close to close the Local Area

Connection Properties window.

NOTE

The IPv6 prefix Fc00:1234:5678:9abc::/64 for the address Fc00:1234:5678:9abc::2

is a ULA—that is, a private non-globally routable address.

The DNS server also needs to have a reverse lookup zone created to allow computers to

register their IPv6 addresses. This is separate from the IPv4 reverse lookup zone created

earlier in the chapter, although it serves the same purpose. To create the IPv6 reverse

lookup zone, perform the following steps:

1. Launch Server Manager on the DNS server.

2. Expand the Roles node, DNS Server node, DNS node, and the server node, and select

the Reverse Lookup Zones node.

3. Right-click the Reverse Lookup Zones node and select New Zone.

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4. Click Next at the Welcome screen.

5. Ensure that Primary Zone and Store the Zone in Active Directory are selected, and

then click Next.

6. Select to replicate to all domain controllers in the forest, and then click Next.

7. Select the IPv6 Reverse Lookup Zone option and click Next.

8. Enter FC00:1234:5678:9abc::/64 for the IPv6 address prefix. The reverse lookup

zone name will be created automatically. Click Next.

9. Allow only secure updates and click Next.

10. Click Finish to complete the task.

Setting Up a DHCPv6 Server on Windows Server 2008 R2

IPv6 is installed and enabled by default in Windows Server 2008 R2, and native IPv6 func-

tionality is already included into Windows Server 2008 R2 DHCP by way of DHCPv6.

In this example, we assume that the Windows Server 2008 R2 server is assigned with the

IPv6 address from the previous example: Fc00:1234:5678:9abc::2. To set up the DHCP role,

execute the following steps:

1. Launch Server Manager and click the Add Roles link.

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2. Read the Before You Begin page and ensure that you have followed the bulleted

items. Click Next if you are ready to continue.

3. On the Server Roles page, click the check box to enter a check mark next to DHCP

Server (as shown in Figure 10.28), and click Next.

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FIGURE 10.28

Selecting the DHCP server role.

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4. A warning message might appear, asking for confirmation to “Install DHCP Server

Without a Static IP Address.” For this example, we have not assigned a static IPv4

address. The wizard is detecting this, and this can be ignored during this example. If

this message appears, click Install DHCP Server Anyway (Not Recommended).

5. Be sure to take the time to read the “Introduction to DHCP Server,” and click Next

when you are ready to continue.

6. The next three sections for IPv4—IPv4 DNS Settings, IPv4 WINS Settings, and DHCP

Scopes—can be bypassed by clicking Next.

7. On the DHCPv6 Stateless Mode page, two options are available. For the Windows

Server 2008 R2 server to issue IPv6 addresses, select Disable DHCPv6 Stateless Mode

for This Server, and click Next.

8. On the DHCP Server Authorization page, specify the account that will be used to

authorize this DHCP server on the network, and click Next.

9. On the Confirmation page, review the settings, and click Install when you are ready

to continue.

10. It is important to not disrupt the installation progress, and allow the installation

to complete.

11. Confirm the installation on the Results page, and click Close.

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The DHCPv6 server is set up, but an IPv6 scope still needs to be configured for the server

to begin assigning addresses.

Setting Up a DHCPv6 Scope on Windows Server 2008 R2

A separate scope is needed to assign IPv6 addresses in DHCP. The following steps show the

administrator how to configure a DHCPv6 scope in Windows Server 2008 R2:

1. Launch Server Manager, expand Roles, and then select DHCP Server.

2. In the DHCP window, expand the server name, and then click IPv6.

3. Right-click on IPv6, and click on New Scope. This opens a New Scope Wizard

window. Click Next to continue.

4. For this example, name the scope “Test IPv6 Scope,” leave the Description field

blank, and click Next to continue.

5. Assuming that the server’s IPv6 address is still Fc00:1234:5678:9abc::2 from the

previous example, enter in a prefix of Fc00:1234:5678:9abc::, leave the Preference

setting at the default setting of 0, and click Next.

6. On the Add Exclusions page, enter :0000 for the start and :ffff for the end.

Exclusions are added to avoid a potential IP address conflict (for example, the server

issuing its own address).

7. Click the Add button, and click Next to continue. See Figure 10.29 for more detail.

8. Review the default settings, and click Next on the Scope Lease page.

How to Configure IPv6 on Windows Server 2008 R2

315

FIGURE 10.29

Adding exclusions.

9. Confirm the settings, ensure that the Yes option button under Activate Scope Now is

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selected, and then click Finish.

Now the DHCP server will begin to assign IPv6 addresses from the scope.

Adding an IPv6 Host Record in Windows Server 2008 R2 DNS

Configuring IPv6 host records in DNS is very similar to configuring IPv4 records. When

configuring IPv6 records in Windows Server 2008 R2 DNS, it is possible to provide the

abbreviated IPv6 addressing, meaning that you are able to use double “::”. The following

steps walk through configuring an AAAA host record for IPv6:

1. Launch the Server Manager, expand the Roles, expand DNS Server, expand DNS, and