IPv6转型：布局下一代互联网 - CSDN文库

需积分: 10 154 浏览量更新于2024-07-30 收藏 2.56MB PDF 举报

“Planning for IPv6”是一本书，由Silvia Hagen撰写，专注于介绍IPv6在商业环境中的应用和实际意义。这本书旨在帮助读者理解IPv6，并为公司的IPv6过渡提供规划指导。 IPv6（互联网协议第六版）是互联网协议的最新版本，它解决了IPv4地址耗尽的问题，提供了几乎无限的地址空间。IPv6的设计目的是提高网络效率，增强安全性，简化网络管理和配置，并支持更多的服务和设备连接到互联网。随着物联网(IoT)和移动设备的迅速发展，IPv6的重要性日益凸显。书中的内容可能涵盖了以下关键知识点： 1. **IPv6的基础知识**：包括IPv6地址结构、地址分配、路由选择和子网划分。IPv6地址长度为128位，通常表示为八组四字符的十六进制数，如2001:0db8:85a3:0000:0000:8a2e:0370:7334。 2. **IPv6与IPv4的区别**：讨论了两种协议在网络层的主要差异，如头部结构、分片机制和邻居发现协议(Neighbor Discovery Protocol, NDP)等。 3. **过渡技术**：介绍如何从IPv4平滑过渡到IPv6，如双栈(Dual Stack)、隧道技术(如6to4、ISATAP、GRE隧道)、转换技术(NAT64/DNS64)等。 4. **IPv6的部署策略**：包括企业网络、数据中心、移动网络和公共互联网的IPv6实施步骤，以及测试和验证过程。 5. **IPv6的安全性**：探讨IPv6相对于IPv4在安全方面的改进，如内置IPsec支持、更强大的认证机制，以及防止某些IPv4时代的攻击。 6. **案例研究**：书中可能包含实际企业或组织成功实施IPv6的案例，以展示IPv6如何提升效率、降低成本并适应未来网络需求。 7. **未来展望**：对IPv6在物联网、云计算、大数据和智能城市等新兴领域的发展潜力进行预测。 8. **最佳实践**：提供规划、设计和实施IPv6网络的实用建议和技巧，以确保平稳过渡并避免常见问题。通过阅读“Planning for IPv6”，读者可以深入了解IPv6的商业价值，学习如何规划和实施IPv6策略，以确保公司在技术发展的潮流中保持领先地位。此外，对于IT专业人士，这本书也将帮助他们掌握IPv6的关键技术和管理挑战，从而更好地服务于组织的需求。

CHAPTER 1

The Business Case

In this first chapter, I’ll discuss the business case and try to put it in a larger context

than usual to open the discussion for new perspectives and opportunities. Resolving

the business case discussions and putting the integration of IPv6 in the right context

paves the way for you to actually focus on the demands of planning for a successful

integration.

Many people hesitate to start the planning phase, probably because it often seems to

be an insurmountable task, with challenges that are way too complex to even start

thinking about it.

While it is true that integration in a larger network is not a no-brainer and takes a lot

of time and careful planning, there is no need to panic or think that you can’t handle

it. Every decent engineer who mastered the introduction of DHCP, VPNs, and NATs

will also master the introduction of IPv6. The difference is that IPv6, as the transport

protocol, touches every component in the network, so the complexity of integrating it

comes from having to consider all the interactions between the different network com-

ponents and services.

But the process can be broken down into single, doable steps, and you don’t have to

complete them in three months if you start early enough. This book provides an outline

to help you determine how you want to go about tackling it.

The Inevitable Business Case Discussion

The discussion around the lack of a business case for IPv6 is historically the most used

good reason to avoid integrating IPv6. The root of this argument seems to lie in the

combination of misunderstandings and a lack of context.

A business case addresses, at a high level, the business need that the project seeks to

meet. It addresses the reasons for the project, the expected business benefits and risks,

the options considered, and the expected costs of the project.

1

To define a business case, you must specify the parameters that qualify it, and what

constitutes a valuable business case may differ depending on the corporate culture. In

other words, what might qualify as a substantial business case in one corporate culture

may not be considered a business case in another culture because the corporate values

are different.

In general, we can say that IPv6 is part of evolving our infrastructure, evolving the

network that transports all data— it is the future highway for our data. So asking for

a business case for IPv6 is like asking for the business case of running a network. But

running our businesses without using scalable, high performance networks is not really

an option anymore. So there is not much choice, we must continue to invest in evolving

our networks, just like we have done since the early days of running networks; other-

wise, they will stop providing useful services for our businesses and hinder our com-

petitiveness at some point in the near future.

The Human Capacity for Predictions and the Business Case of Evolution

Our business case calculations and the common opinion that IPv6 has no business case

are based on expectations and predictions. What we think will be happening in three

to five years is what we base our judgments on.

If we look at history, though, we see that our capacity for accurate predictions is pretty

limited. Back in the early 1980s, studies were conducted to determine the likelihood

that in the future there would be a computer on every desk of an organization. The

results showed that this was very unlikely. But only a few years later, a computer on

every desk was a reality, and soon people often had not just one, but multiple

computers.

In the early 1990s, studies showed that it was highly unlikely that everyone would soon

have a cell phone. After all, the early versions were heavy and looked like sewing ma-

chines. Only a few years later, however, schools had to prevent students from using

their cell phones during lectures and exams because they were using them to exchange

results with each other. And at the same time, nobody spotted the business case for

SMS (text messages). It was mainly a leftover from development, and it simply wasn’t

removed from production. Yet, SMS hit the world, became widely used overnight, and

today is making gigantic profits for many organizations.

So are we good at making predictions and determining business cases? Obviously not.

Did someone foresee the emergence and success of Google, Skype, Facebook, and

Twitter? Was there a careful business case defined before these technologies were de-

veloped? It seems that services can become very successful even if we haven’t thought

about a business case beforehand; and in fact, had the developers tried to make a busi-

ness case for the aforementioned technologies, they may well have arrived at the con-

clusion that there wasn’t one and opted not to deploy the service.

2 | Chapter 1: The Business Case

This is how evolution works. Technology and science are an expression of the evolution

of human consciousness. And because this is a collective factor, it is highly unpredict-

able. In the 1920s, for instance, it was a huge problem that more and more people were

starting to use horses for transport. Initially, only the rich could afford traveling by

horse, but soon everyone was using them. Trend analysts predicted that mankind

would soon drown in horse dung. This was a serious concern, and nobody could think

of a useful answer to this problem. The solution came from a very unexpected angle.

It was the invention of the car, and it revolutionized not only the transportation system,

but also the whole industry. This example confirms Albert Einstein’s assertion that “no

problem can be solved from the same level of consciousness that created it.” Now we

face new problems that have emerged from the invention of the car, and just like with

the horse dung dilemma, we don’t really know how to solve them. Chances are, the

true solution will come from an unexpected evolutionary angle again.

For the car to be used widely, we needed better streets. Today we have an extended

high-level street system in large parts of the world to enable transport for all the cars

in use. Was there a business case for building all these streets? I guess nobody asked

the question in this way; otherwise, we would probably not have our current street

system.

Some creative developers designed IPv4 in the early 1970s. Their goal was to develop

a protocol to connect a handful of computers. They managed to create a protocol that

is the basic transport for our gigantic modern-day Internet (approximately 2 billion

users in 2011, growing exponentially; up from 360 million in 2001). But these devel-

opers did not have anything like the Internet in mind. There was no business plan and

no business case for the Internet. It just happened during the 1990s; the world picked

it up and started using it on a widespread scale, from online ecommerce in the

mid-1990s to today’s social networking and cloud services. And the IETF (Internet

Engineering Task Force) responded to the market demand and developed all the ex-

tensions to IPv4 that we currently use.

There was no business case for the Internet because evolution doesn’t

need a business case. Evolution just happens without asking us.

And by the way, don’t think this is the end—evolution is also never-ending. For ex-

ample, Vint Cerf, the “father of the Internet,” and one of the guys who developed IPv4

in those early days, is now working on standardizing the Interplanetary Communica-

tion protocol based on the Bundle Protocol (RFC 5050); first implementations are cur-

rently available and tests are being run. So, while we may think this sounds crazy be-

cause we’re focused on planetary issues like danger from atomic power, natural cata-

strophes, wars, and financial crisis, some visionaries are working on the future— with

no business case, but fueled by evolutionary impulses.

The Inevitable Business Case Discussion | 3

The Internet has definitely reshaped our world, changed the way we communicate,

impacted the way we approach business and education, broken down hierarchies, and

established an important ingredient for globalization. It happened because we all jum-

ped on the bandwagon, saw it as a useful tool, and started investing and participating

in building and extending it. It is a global collective collaboration.

So what is the business case for IPv6? If you want, we can put it like this:

The business case for IPv6 is the continued use and expansion of the Internet.

Without the introduction of IPv6, the Internet cannot continue to grow now that the

IPv4 address space is definitely exhausted. This means that everyone who uses and

profits from the Internet has to do his part in helping integrate IPv6. Integration too

will have to be a global collective collaboration. For some corporate cultures, this might

be a sufficient business case.

But let’s go on and analyze the business case question in detail in a more practical

context.

IPv6 Has No Immediate Business Case for Many

Corporations and organizations have maintained networks for many years. When we

started maintaining them, mostly in the early 1990s, the networks were small and few

were the tools we had available to manage them. Soon the number of network devices

and the variety of network services were growing exponentially. At the same time, the

requirements for management, administration, and security were increasing. When we

started designing our IPv4-based networks, we did not have a real understanding of

what lay ahead. But we learned while growing the networks and whenever we faced

new challenges, we finally found solutions; and when public demand became obvious,

the IETF developed all the useful extensions to the IPv4 protocol, such as DNS, DHCP,

IPSec, and NAT.

With regard to the business case, we can say that the evolution, extension, and opti-

mization of our network infrastructure always came at a cost. In other words, evolving

our network has always been part of our returning budget—costs used to maintain a

state-of-the-art infrastructure capable of running state-of-the-art services. We have to

extend our infrastructure for more bandwidth constantly, as the services running on

top continue to consume more bandwidth. We have to replace network devices in

regular cycles, and when it comes to replacing core routers, this is usually a substantial

cost factor. We also have to invest a lot into securing our networks and providing an

infrastructure that can accommodate the demands of mobile users. And we constantly

upgrade operating systems to newer versions, such as the currently ongoing migration

from Windows Server 2003 to Windows Server 2008.

Do all these investments have a business case? What is the business case in upgrading

a core router? What is the business case in upgrading a server operating system? Both

do their job—they route or run services—so why should we invest in upgrading them?

4 | Chapter 1: The Business Case

剩余79页未读，继续阅读

dapangf1

粉丝: 0

最新资源