Home > Articles > Networking

A Practical Guide to Advanced Networking: IPv6

This chapter looks at IPv6, the IP addressing system that has been developed to replace IPv4.
This chapter is from the book

Address space for IPv4 is quickly running out due to the rapid growth of the Internet and the development of new Internet-compatible mobile technologies. Examples of this include the IP addressable telephone, wireless personal digital assistants (PDAs), cell phones, game consoles, and home-networking systems. There have been many predictions of when the IPv4 address pool will be exhausted. The answer to this question is not clear. Techniques such as Network Address Translation/Port Address Translation (NAT/PAT), Dynamic Host Control Protocol (DHCP), and Classless Inter-Domain Routing (CIDR) have been implemented to prolong the life of IPv4. These techniques reuse the existing IPv4 address space and handle the address space allocation more efficiently.

A solution to the limited number of available IPv4 addresses is to migrate to IPv6. IP version 6 (IPv6) is the solution proposed by the Internet Engineering Task Force (IETF) for expanding the possible number of IP addresses to accommodate the growing users on the Internet. IPv6, introduced in 1999, is also called IPng.

This chapter provides a comparison of IPv6 and IPv4 in Section 8-1. The structure of the IPv6 address is examined in Section 8-2. Concepts such as the network prefix and the prefix length are examined. IPv6 network settings are examined in Section 8-3. Steps for configuring IPv6 in both the Windows and Mac OS X environments are examined. The steps for configuring a router to run IPv6 are examined in section 8-4. This chapter concludes with a look at troubleshooting the IPv6 connection in Section 8-5.

8-1. Comparison of IPv6 and IPv4

IPv4 and IPv6 are not compatible technologies, and they cannot communicate directly with each other. So, before migrating to an IPv6 environment, the network devices and network equipment need to be IPv6 compatible or enabled. Most likely new network hardware and software will have to be acquired to make the network IPv6 ready. A good migration plan has to be developed to prepare for IPv6. The investment of time, money, and training is required for a successful adoption of IPv6.

The size of the IPv6 address is increased to 128 bits, which is four times larger than the 32-bit address space IPv4 is using. This significantly increases the number of available IP addresses. By doing this, the theoretical number of unique addresses increases from 4.3x109 (IPv4) to 3.4x1038 in IPv6. This is a staggering number considering the world population is 7x109 people.

Increasing the number of bits for the address also results in changing the IP header size. The IPv4 datagram is shown in Figure 8-1. A datagram is a self-contained entity that carries sufficient information to be routed from source to destination without relying on previous data exchanges between the source and destination computers or the transporting network.

Figure 8-1

Figure 8-1. The IPv4 Datagram (160 bits-96 bits for header fields)

The IPv4 header size is comprised of the information detailed in Figure 8-1. A total of 64 bits are used to define the source and destination IP addresses. Note that both the source and destination addresses are 32 bits in length. The combination of the two gives 64 bits. The total length of the IPv4 header is 160 bits; therefore, this means 160 – 64 = 96 bits are used to make up the remaining fields.

Figure 8-2. shows the IPv6 datagram. The IPv6 header size is 320 bits; however, 256 bits are used to define the source and destination IPv6 addresses. This means that 64 bits are used to define the remaining field as compared to 96 bits for IPv4.

Figure 8-2

Figure 8-2. The IPv6 Datagram (320 bits-64 bits for header fileds)

The IPv6 header has been simplified resulting in less header fields than in IPv4. This is designed to make packet processing more efficient by routers and other network equipments. One noticeably missing header field in IPv6 is the checksum field. This means there is no checksum calculation done by the routers in the path. This increases the routing performance and efficiency. The error detection is now done at the link layer and transport layer. In IPv4, the TCP transport layer is required to check the integrity of the packet by doing a checksum calculation. The same cannot be said for the UDP transport layer because the checksum is optional. Now, the checksums are required for both transport layers in IPv6.

One new feature that is built in with IPv6 is the IP security (IPsec). IPsec is the IETF standard for securing the IP communications between the network nodes by authenticating and encrypting the session. When using IPv4, a secure network IP communication link generally has to be initiated to provide security similar to an IPSec application. In IPv6, every node is enabled with the IPSec feature. This makes creating end-to-end IPSec sessions much easier to establish. In addition, IPSec feature is a part of the extension headers. In IPv6, there is a mandatory IPv6 main header and then there could be an extension header or extension headers. All options and special purposed fields can be provisioned into extension headers when needed. IPSec is one of the special options. This is how IPv6 simplifies its header fields.

Another giant step forward taken by IPv6 is the elimination of the broadcast. Broadcasts can cause many problems in computer networks. When a broadcast happens, every computer on the network is interrupted, even if only two computers are involved. The worst case situation is a broadcast storm. When this happens, the performance on a network is severely degraded, and it can bring down an entire network. IPv6 does not use broadcasts. It uses multicasts instead. A multicast is used in the core of many functions in IPv6. The multicast addresses are allocated from the multicast block. Any address starting with “1111 1111” in binary or “FF” in colon hexadecimal notation is an IPv6 multicast address. The concept of colon hexadecimal notation is discussed in Section 8-2. Even though there is no such thing as broadcast, there is a multicast address to the all-host multicast group.

Stateless address autoconfiguration (SLAAC) is another important feature of IPv6. This feature allows for a server-less basic network configuration of the IPv6 computers. With IPv4, a computer generally obtains its network settings from a DHCP server. With IPv6, a computer can automatically configure its network settings without a DHCP server by sending a solicitation message to its IPv6 router. The router then sends back its advertisement message, which contains the prefix information that the computer can use to create its own IPv6 address. This feature significantly helps simplify the deployment of the IPv6 devices, especially in the transient environments such as airports, train stations, stadiums, hotspots, and so on.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020