Routing

IPv6 Transition Technologies

Table C-10 IPv6 Transition Technologies RFCs

For the latest list of RFCs and Internet drafts describing IPv6, see the IETF IPv6 Working Group at http://www.ietf.org/html.charters/OLD/ipv6-charter.html and the IETF IPv6 Operations Working Group at http://www.ietf.org/html.charters/v6ops-charter.html.

For additional RFCs, see the IETF Request for Comments Web page at http://www.ietf.org/ rfc.html.

418 Understanding IPv6, Second Edition

The IPv6 header is designed for minimal overhead and optimal processing speed at intermediate routers.

IPv6 Neighbor Discovery (ND) replaces the broadcast-based Address Resolution Protocol (ARP) with unicast and multicast ND messages. Common neighbor operations such as address resolution involve very few nodes.

IPv6 hosts are self-configuring and do not require a DHCPv6 server to discover addresses and other configuration information, reducing host startup times.

5.Explain how NATs prevent peer-to-peer applications from working properly.

Because each peer behind a NAT is represented by two addresses (a public address and a private address), peers cannot connect without manually configuring the NAT or relay address information about each other without making the peer-to-peer application NAT-aware.

6.What are the key technical benefits of deploying IPv6 now?

You will be able to take advantage of a much larger address space.

You can get public IPv6 address space in areas of the world that have few available public IPv4 addresses.

IPv6 restores true end-to-end communication without intermediate translation. Peer- to-peer applications can now connect without compensating for one or more NATs between peers.

IPv6 forwarding is more efficient and is address-scope aware.

7.What are the key business benefits of deploying IPv6 now?

IPv6 guarantees the future growth of the Internet by providing enough public addresses for the foreseeable future that can be allocated based on regional connectivity needs.

IPv6 simplifies connectivity by creating a single, global addressing scheme and removing disjoint address spaces.

IPv6 eliminates the need for public address conservation technologies such as NATs and their inherent complications for end-to-end connectivity.

IPv6 requires support for IPsec headers, defining a single standard to provide end-to-end protection of IPv6 packets across intranets or the IPv6 Internet.

Chapter 2: IPv6 Protocol for Windows Server 2008 and Windows Vista

1.List and describe the features of the IPv6 protocol for IPv6 transition.

Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) allows IPv6/IPv4 hosts on an IPv4-only portion of an intranet to use unicast IPv6 traffic to communicate with each other and with native IPv6 nodes on an IPv6-capable portion of the intranet.

6to4 allows a host and a site to use unicast IPv6 traffic to communicate with each other across the IPv4 Internet and with native IPv6 nodes on the IPv6 Internet.

Teredo allows IPv6/IPv4 hosts on the IPv4 Internet to use unicast IPv6 traffic to communicate with each other and with nodes on the IPv6 Internet, even when the IPv6/IPv4 hosts are behind a NAT.

PortProxy functions as a Transmission Control Protocol (TCP) proxy to facilitate the communication between nodes or applications that cannot connect using a common Internet layer protocol (IPv4 or IPv6).

2.What are the two ways to configure the IPv6 protocol for Windows Server 2008 and Windows Vista?

For most hosts, no configuration is required because stateless address autoconfiguration automatically configures addresses, routes, and other settings. To manually configure the IPv6 protocol for Windows Server 2008 and Windows Vista, use the properties of the Internet Protocol version 6 (TCP/IPv6) component in the Network Connections folder or at the Windows command prompt with commands in the netsh interface ipv6 context.

3.A network administrator wants to disable all 6to4 and Teredo tunnel interfaces for computers running Windows Server 2008 or Windows Vista. What is the correct value of the

DisabledComponents registry value?

To disable 6to4 and Teredo interfaces, you must set bits 1 and 3 to 1, forming the binary number 00001010, or 0xA. Therefore, set DisabledComponents to 0xA.

4.Describe the purpose of Link-Local Multicast Name Resolution (LLMNR) and when it is used as the primary method for name resolution for IPv6 addresses.

LLMNR allows IPv6 hosts on a subnet to resolve each other’s names through an exchange of a multicast query and unicast response messages. LLMNR is the primary method of name resolution when a Domain Name System (DNS) server is not available, such as on an ad hoc wireless network.

5.Under what circumstances will an IPv6 router running Windows Server 2008 or Windows Vista advertise itself as a default router?

By default, an IPv6 router running Windows Server 2008 or Windows Vista advertises itself as a default router only if it has a default route that is configured to be published.

6.List how the common TCP/IP troubleshooting tools have been enhanced to support IPv6 in Windows Server 2008 and Windows Vista.

Ipconfig.exe displays both IPv4 and IPv6 configurations.

Route.exe displays and allows modifications to both IPv4 and IPv6 routing tables.

Ping.exe uses both Internet Control Message Protocol for IPv4 (ICMPv4) Echo and Internet Control Message Protocol for IPv6 (ICMPv6) Echo Request messages and supports additional options for IPv6.