Outlining Windows Server 2008 R2 IPv6 Support

2/3/2011 7:33:11 PM
When the original structure of the Internet was taking shape, an addressing scheme was formulated to scale to a large number of hosts. From this thinking came the original design of the Internet Protocol, which included theoretical support for around 4 billion addresses, or 232. The thinking at the time was that this would be more than enough addresses for all hosts on the Internet. This original design gave birth to the IP address structure that is common today, known as dotted-decimal format (such as At the time, this address space filled the addressing needs of the Internet. However, it was quickly discovered that the range of addresses was inadequate, and stopgap measures such as Network Address Translation (NAT) were required to make more efficient use of the available addresses.

In addition to an inadequate supply of available addresses, the Internet Protocol version 4 (IPv4), as it is known, did not handle routing, IPSec, and QoS support very efficiently. The need for a replacement to IPv4 was evident.

In the early ’90s, a new version of the Internet Protocol, known as Internet Protocol version 6 (IPv6), was formulated. This design had several functional advantages to IPv4, namely a much larger pool of addresses from which to choose by allowing for 2128 theoretical IP addresses, or over 340 undecillion, which gives more than enough IP addresses for every square centimeter on the earth. This protocol is the future of Internet addressing, and it’s vitally important that an operating system support it.

Windows Server 2008 R2 comes with a version of IPv6 installed, and is fully supported as part of the operating system. Given the complexity of IPv6, it will undoubtedly take some time before it is adopted widely, but understanding that the support exists is the first step toward deploying it widely.

Defining the Structure of IPv6

To say that IPv6 is complicated is an understatement. Attempting to understand IPv4 has been difficult enough for network engineers; throw in hexadecimal 128-bit addresses, and life becomes much more interesting. At a minimum, however, the basics of IPv6 must be understood as future networks will use the protocol more and more as time goes by.

IPv6 was written to solve many of the problems that persist on the modern Internet today. The most notable areas that IPv6 improved upon are the following:

  • Vastly improved address space— The differences between the available addresses from IPv4 to IPv6 are literally exponential. Without taking into account loss because of subnetting and other factors, IPv4 could support up to 4,294,967,296 nodes. IPv6, on the other hand, supports up to 340,282,366,920,938,463,463,374,607,431,768,211,456 nodes. Even taking into account IP addresses reserved for overhead, IPv6 authors were obviously thinking ahead and wanted to make sure that they wouldn’t run out of space again.

  • Improved network headers— The header for IPv6 packets has been streamlined, standardized in size, and optimized. To illustrate, even though the address is four times as long as an IPv4 address, the header is only twice the size. In addition, by having a standardized header size, routers can more efficiently handle IPv6 traffic than they could with IPv4.

  • Native support for automatic address configuration— In environments where manual addressing of clients is not supported or desired, automatic configuration of IPv6 addresses on clients is natively built in to the protocol. This technology is the IPv6 equivalent to the Automatic Private Internet Protocol Addressing (APIPA) feature added to Windows for IPv4 addresses.

  • Integrated support for IPSec and QoS— IPv6 contains native support for IPSec encryption technologies and Quality of Service (QoS) network traffic optimization approaches, improving their functionality and expanding their capabilities.

Understanding IPv6 Addressing

An IPv6 address, as previously mentioned, is 128 bits long, as compared with IPv4’s 32-bit addresses. The address itself uses hexadecimal format to shorten the nonbinary written form. Take, for example, the following 128-bit IPv6 address written in binary:



The first step in creating the nonbinary form of the address is to divide the number in 16-bit values, as follows:

1111111010000000 0000000000000000

0000000000000000 0000000000000000

0000001000001100 0010100111111111

1111111001000100 0111111000111111

Each 16-bit value is then converted to hexadecimal format to produce the IPv6 address:


Luckily, the authors of IPv6 included ways of writing IPv6 addresses in shorthand by allowing for the removal of zero values that come before other values. For example, in the address listed previously, the 020C value becomes simply 20C when abbreviated. In addition to this form of shorthand, IPv6 allows continuous fields of zeros to be abbreviated by using a double colon. This can only occur once in an address, but can greatly simplify the overall address. The example used previously then becomes the following:



It is futile to attempt to memorize IPv6 addresses, and converting hexadecimal to decimal format is often best accomplished via a calculator for most people. This has proven to be one of the disadvantages of IPv6 addressing for many administrators.

IPv6 addresses operate much in the same way as IPv4 addresses, with the larger network nodes indicated by the first string of values and the individual interfaces illustrated by the numbers on the right. By following the same principles as IPv4, a better understanding of IPv6 can be achieved.

Migrating to IPv6

The migration to IPv6 has been, and will continue to be, a slow and gradual process. In addition, support for IPv4 during and after a migration must still be considered for a considerable period of time. It is consequently important to understand the tools and techniques available to maintain both IPv4 and IPv6 infrastructure in place during a migration process.

Even though IPv6 is installed by default on Windows Server 2008 R2, IPv4 support remains. This allows for a period of time in which both protocols are supported. After migrating completely to IPv6, however, connectivity to IPv4 nodes that exist outside of the network (on the Internet, for example) must still be maintained. This support can be accomplished through the deployment of IPv6 tunneling technologies.

Windows Server 2008 R2 tunneling technology consists of two separate technologies. The first technology, the Intrasite Automatic Tunnel Addressing Protocol (ISATAP), allows for intrasite tunnels to be created between pools of IPv6 connectivity internally in an organization. The second technology is known as 6to4, which provides for automatic intersite tunnels between IPv6 nodes on disparate networks, such as across the Internet. Deploying one or both of these technologies is a must in the initial stages of IPv6 industry adoption.

Making the Leap to IPv6

Understanding a new protocol implementation is not at the top of most people’s wish lists. In many cases, improvements such as improved routing, support for IPSec, no NAT requirements, and so on are not enough to convince organizations to make the change. The process of change is inevitable, however, as the number of available nodes on the IPv4 model decreases. Consequently, it’s good to know that Windows Server 2008 R2 is well prepared for the eventual adoption of IPv6.

  •  Windows Server 2008 : Active Directory Infrastructure - Planning Replication Topology
  •  Windows 7 : Protecting Your Computer While Browsing (part 5)
  •  Windows 7 : Protecting Your Computer While Browsing (part 4) - Restricting Permissions Using Security Zones
  •  Windows 7 : Protecting Your Computer While Browsing (part 3)
  •  Windows 7 : Protecting Your Computer While Browsing (part 2) - Viewing and Managing Browsing History
  •  Windows 7 : Protecting Your Computer While Browsing (part 1) - Viewing and Managing Add-Ons
  •  Windows Server 2008 : Understanding Active Directory Sites (part 2)
  •  Windows Server 2008 : Understanding Active Directory Sites (part 1)
  •  Windows Server 2008 : Understanding AD DS Replication in Depth
  •  Programming Excel with VBA and .NET : Knowing the Basics - Classes and Modules
  •  Windows 7 : Indexing Your Computer for Faster Searches (part 3) - Optimizing File Properties for Indexing
  •  Windows 7 : Indexing Your Computer for Faster Searches (part 2) - Specifying Files Types to Include or Exclude
  •  Windows 7 : Indexing Your Computer for Faster Searches (part 1) - Adding or Removing Indexed Locations
  •  Windows Server 2008 : Designing Organizational Unit and Group Structure - Exploring Sample Design Models
  •  Windows Server 2008 : Designing Organizational Unit and Group Structure - Understanding Group Design
  •  Windows Server 2008 : Designing Organizational Unit and Group Structure - Group Policies and OU Design
  •  Windows 7 : Searching Your Computer (part 2) - Search Filters
  •  Windows 7 : Searching Your Computer (part 1)
  •  Windows 7 : Putting Windows Explorer to Work for You
  •  Windows Server 2008: Using OUs to Delegate Administration
    Top 10
    Quiet PC Serenity Gamer - Take On All Challengers
    Roccat Kone Pure – Accurate & Comfortable
    Samsung 840 Pro Series SSD 512GB
    Scan 3XS Performance GTX - The Most Powerful Gaming PC
    Motorola MotoSmart - Low-Cost Handset
    Motorola RAZRi - Excellent UI Skin
    The Xperia T - Remarkable In How Unremarkable It Is (Part 2)
    The Xperia T - Remarkable In How Unremarkable It Is (Part 1)
    Magnepan DWM Woofer Review
    Livescribe Sky - Sync Your Handwritten Notes
    Most View
    Windows Vista : Performance - Hard Disk (part 1) - A Defragmentation Crash Course
    Microsoft Dynamics AX 2009 : Building Lookups - Picking a color
    Choosing a super-zoom camera (part 5)
    Apple Society – Less Never More
    Microsoft Enterprise Library : Non-Formatted Trace Listeners (part 1) - Creating and Using Logentry Objects, Capturing Unprocessed Events and Logging Errors
    Building LOB Applications : Databinding in XAML
    Creating and Managing Views in SQL Server 2008 : Managing Views, Data Modifications and Views
    Buying Guide: Gaming PCs For Hardcore Gamers' Dreams (Part 2) - Cyberpower Fang III Rattler, Dino PC Maxosaurus 3570K
    Vigor 2850n
    ZTE Grand X - Big And Bold
    The 30 Most Important Technology Trends (Part 2)
    The Tablet Wars (Part 2) - Kindle Fire HD
    Gorilla Gondola
    How To Set Up The Ultimate Steam Box (Part 2)
    Programming .NET Security : Using the Code-Access Security Policy Tool (part 2) - Evaluating Security Policy
    Windows Phone 7 Development : Building a Phone Client to Access a Cloud Service (part 5) - Deploying the Service to Windows Azure
    The Hit List - Comprehensive Task Manager
    Windows Vista : Customizing Windows PE Boot Images (part 1) - Working with ImageX
    Programming Microsoft SQL Server 2005 : The XML Data Type (part 3) - XML Indexes
    The Art of SEO : How Links Influence Search Engine Rankings (part 2) - Additional Factors That Influence Link Value