Über die Autorin bzw. den Autor

TIMOTHY ROONEY has worked with IP technologies in various capacities over the last sixteen years, including systems engineering and development. He has an extensive background not only in IP, but also in telecommunications, wireless services, and software, having worked at Bell Laboratories, AT&T Wireless, Lucent Technologies, and BT. In his current role as Director of Product Management with BT Diamond IP, Rooney is responsible for the overall BT Diamond IP product life cycle, managing product features and releases, as well as supporting sales and marketing.

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A hands-on resource for rigorous, state-of-the-art management of today's IP networks

Effective IP address management (IPAM) is a key ingredient in an enterprise or service provider IP network management strategy. The practice entails the application of network management disciplines to Internet Protocol (IP) address space and associated network services, namely Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS).

As a natural follow-up to the author's previous book, Introduction to IP Address Management, this resource uniquely unifies all three foundational IP address management technologies, fully addressing their interrelationships and their cohesive management. It also describes the relevant protocols, configuration examples for the market-leading reference implementations from the Internet Systems Consortium (ISC), and techniques that can be employed to structure, monitor, secure, and manage them.

The first part of the book provides a detailed overview of IPv4, IPv6, and IP allocation and subnetting techniques. In the second, DHCP for IPv4 and IPv6 is reviewed, with explanations of applications that rely on DHCP (such as VoIP device provisioning, broadband access provisioning, and PXE client initialization), DHCP server deployment strategies, and DHCP and relevant network access security. The third part reviews the DNS protocol, DNS applications (such as name resolution, services location, ENUM, anti-spam techniques via black/white listing, and Sender ID), deployment strategies and associated configurations, and security.

Finally, the text brings together the preceding parts, discussing techniques for cohesively managing IP address space, including impacts to DHCP and DNS. Everyday IP address management functions are described including IP address allocation and assignment, renumbering, inventory assurance, fault management, performance monitoring, and disaster recovery as are coexistence strategies.

IP Address Management Principles and Practice utilizes realistic scenarios throughout to further enhance the learning process. It will educate readers responsible for managing IP address space and DHCP and DNS server configurations, such as IP network planners, engineers, and managers, including those who need to deploy IPv6 networks. It is also ideal for those responsible for managing an IP network with over 5,000 IP nodes, several DNS or DHCP servers, mixed DHCP and DNS vendor deployments, or IPv4 and IPv6.

Aus dem Klappentext

A hands-on resource for rigorous, state-of-the-art management of today's IP networks

Effective IP address management (IPAM) is a key ingredient in an enterprise or service provider IP network management strategy. The practice entails the application of network management disciplines to Internet Protocol (IP) address space and associated network services, namely Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS).

As a natural follow-up to the author's previous book, Introduction to IP Address Management, this resource uniquely unifies all three foundational IP address management technologies, fully addressing their interrelationships and their cohesive management. It also describes the relevant protocols, configuration examples for the market-leading reference implementations from the Internet Systems Consortium (ISC), and techniques that can be employed to structure, monitor, secure, and manage them.

The first part of the book provides a detailed overview of IPv4, IPv6, and IP allocation and subnetting techniques. In the second, DHCP for IPv4 and IPv6 is reviewed, with explanations of applications that rely on DHCP (such as VoIP device provisioning, broadband access provisioning, and PXE client initialization), DHCP server deployment strategies, and DHCP and relevant network access security. The third part reviews the DNS protocol, DNS applications (such as name resolution, services location, ENUM, anti-spam techniques via black/white listing, and Sender ID), deployment strategies and associated configurations, and security.

Finally, the text brings together the preceding parts, discussing techniques for cohesively managing IP address space, including impacts to DHCP and DNS. Everyday IP address management functions are described—including IP address allocation and assignment, renumbering, inventory assurance, fault management, performance monitoring, and disaster recovery—as are coexistence strategies.

IP Address Management Principles and Practice utilizes realistic scenarios throughout to further enhance the learning process. It will educate readers responsible for managing IP address space and DHCP and DNS server configurations, such as IP network planners, engineers, and managers, including those who need to deploy IPv6 networks. It is also ideal for those responsible for managing an IP network with over 5,000 IP nodes, several DNS or DHCP servers, mixed DHCP and DNS vendor deployments, or IPv4 and IPv6.

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IP Address Management: Principles and Practice

John Wiley & Sons

Chapter One

1.1 HIGHLIGHTS OF INTERNET PROTOCOL HISTORY

The Internet Protocol (IP) has changed everything. In my early days at AT&T Bell Laboratories in the mid-1980s when we used dumb terminals to connect to a mainframe, the field of networking was just beginning to enable the distribution of intelligence from a centralized mainframe to networked servers, routers, and ultimately personal computers. Now that I've dated myself, a little later, many rival networking technologies were competing for enterprise deployments with no clear leader. Deployment of disparate networking protocols and technologies inhibited communications among organizations, until during the 1990s the Internet Protocol, thanks to the widespread embrace of the Internet, became the world's de facto networking protocol.

Today, the Internet Protocol is the most widely deployed network layer protocol worldwide. Emerging from a U.S. government sponsored networking project for the U.S. Department of Defense begun in the 1960s, the Transmission Control Protocol/Internet Protocol (TCP/IP) suite has evolved and scaled to support networks from hundreds of computers to hundreds of millions today. In fact, according to Internet Systems Consortium (ISC) surveys, the number of devices or hosts on the Internet exceeded 730 million as of early 2010 with average annual additions of over 75 million hosts per year over each of the past 6 years (see Figure 1.1). The fact that the Internet has scaled rather seamlessly from a research project to a network of over 730 million computers is a testament to the vision of its developers and robustness of their underlying technology design.

The Internet Protocol was "initially" defined in 1980 in Request for Comments (RFC) 760 (1) and 791 (2), edited by the venerable Jon Postel. We quote "initially" because as Mr. Postel pointed out in his preface, RFC 791 is based on six earlier editions of the ARPA (Advanced Research Projects Agency, a U.S. Department of Defense agency) Internet Protocol, though it is referred to in the RFC as version 4 (IPv4). RFC 791 states that the Internet Protocol performs two basic functions: addressing and fragmentation. While this may appear to trivialize the many additional functions and features of the Internet Protocol implemented then and since, it actually highlights the importance of these two major topics for any protocol designer. Fragmentation deals with splitting messages into a number of IP packets so that they can be transmitted over networks that have limited packet size constraints, and reassembly of packets at the destination in the proper order. Addressing is of course one of the key topics of this book, so assuring unique addressability of hosts requiring reachability is critical to basic protocol operation.

The Internet has become an indispensable tool for daily personal and business productivity with such applications as email, social networking, web browsing, wireless access, and voice communications. The Internet has indeed become a key element of modern society. And in case you're interested, the term "Internet" evolved from the lower case form of the term used by the early developers of Internet technology to refer to communications among interconnected networks or "internets."

Today, the capitalized "Internet," the global Internet that we use on a daily basis, has become a massive network of interconnected networks. Getting all of these networks and hosts on them to cooperate and exchange user communications efficiently requires adherence to a set of rules for such communications. This set of rules, this protocol, defines the method of identifying each host or endpoint and how to get information from point A to point B over a network. The Internet Protocol specifies such rules for communication using the vehicle of IP packets, each of which is prefixed with an IP header.

1.1.1 The IP Header

The IP layer within the TCP/IP protocol suite adds an IP header to the data it receives from the TCP or UDP transport layer. This IP header is analyzed by routers along the path to the final destination to ultimately deliver each IP packet to its final destination, identified by the destination IP address in the header. RFC 791 defined the IP address structure as consisting of 32 bits comprised of a network number followed by a local address. The address is conveyed in the header of every IP packet. Figure 1.2 illustrates the fields of the IP header. Every IP packet contains an IP header, followed by the data contents within the packet, including higher layer protocol control information.

Version. The Internet Protocol version, 4 in this case.

Header Length (Internet Header Length, IHL). Length of the IP header in 32-bit units called "words." For example, the minimum header length is 5, highlighted in Figure 1.2 as the lightly shaded fields, which consists of 5 words x 32 bits/ word = 160 bits.

Type of Service. Parameters related to the packet's quality of service (QoS). Initially defined as ToS (type of service), this field consisted of a 3-bit precedence field to enable specification of the relative importance of a particular packet, and another 3 bits to request low delay, high throughput, or high reliability, respectively.

The original ToS field has been redefined via RFC 2474, "Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Header" (177). The DS field, or differentiated services field, provides a 6-bit code point (DSCP, differentiated services code point) field with the remaining 2 bits unused. The code point maps to a predefined service, which in turn is associated with a level of service provided by the network. As new code points are defined with respective services treatment by the Internet authorities, IP routers can apply the routing treatment corresponding to the defined code point to apply higher priority handling for latency-sensitive applications, for example.

Total Length. Length of the entire IP packet in bytes (octets).

Identification. Value given to each packet to facilitate reassembly of packet fragments at the receiving end.

Flags. This 3-bit field is defined as follows:

• Bit 0 is reserved and must be 0. • Bit 1—Don't Fragment—indicates that this packet cannot be fragmented. • Bit 2—More Fragments—indicates that this packet is a fragment, though this is not the last fragment.

Fragment Offset. Identifies the location of this fragment relative to the beginning of the original packet in units of 64-bit "double words."

Time to Live (TTL). A counter decremented upon each routing hop; once the TTL reaches zero, the packet is discarded. This parameter prevents packets from circulating on the Internet forever!

Protocol. The upper layer protocol that shall receive this packet after IP processing, for example, TCP or UDP.

Header Checksum. A checksum value calculated over the header bits only to verify that the header is not corrupted.

Source IP Address. The IP address of the sender of this packet.

Destination IP Address. The IP address of the intended recipient of this packet.

Options. Optional field containing...