Heritage Series ADSL Bridge/ Router

8-5

DHCP Server Operation

8.4.1 Network topology

Declarations about network topology include the shared-networkand the subnet declarations. If clients on a subnet are to be assigned addresses dynamically, a range declaration must appear within the subnet declaration. For clients with statically assigned addresses, or for installations where only known clients will be served, each such client must have a host declaration. If parameters are to be applied to a group of declarations which are not related strictly on a per-subnet basis, the group declaration can be used.

For every subnet which will be served, and for every subnet to which the DHCP server is connected, there must be one subnet declaration, which informs DHCP of the addresses present on that subnet. A subnet declaration is required for each subnet even if no addresses will be dynamically allocated on that subnet.

Some installations have physical networks on which more than one IP subnet operates. For example, if there is a site-wide requirement that 8-bit subnet masks be used, but a department with a single physical ethernet network expands to the point where it has more than 254 nodes, it may be necessary to run two 8-bit subnets on the same ethernet until such time as a new physical network can be added. In this case, the subnet declarations for these two networks may be enclosed in a shared-networkdeclaration. Some sites may have departments which have clients on more than one subnet, but it may be desirable to offer those clients a uniform set of parameters which are different than what would be offered to clients from other departments on the same subnet. For clients which will be declared explicitly with host declarations, these declarations can be enclosed in a group declaration along with the parameters which are common to that department. For clients whose addresses will be dynamically assigned, there is currently no way to group parameter assignments other than by network topology. When a client is to be booted, its boot parameters are determined by first consulting that client’s host declaration (if any), then consulting the group declaration (if any) which enclosed that host declaration, then consulting the subnet declaration for the subnet on which the client is booting, then consulting the shared-networkdeclaration (if any) containing that subnet, and finally consulting the top-level parameters which may be specified outside of any declaration. When DHCP tries to find a host declaration for a client, it first looks for a host declaration which has a fixed-addressparameter which matches the subnet or shared network

Page 127 Page 129
Page 128
Image 128
IBM Heritage user manual Network topology
Page 127 Page 129

Heritage specifications

IBM, or International Business Machines Corporation, is a global leader in technology and consulting, with a heritage that spans over a century. Established in 1911, IBM initially emerged from a merger of four companies, and it has since evolved into one of the most influential players in the tech industry.

One of the main features of IBM’s legacy is its commitment to innovation. The company has a long history of technological breakthroughs, including the development of the first programmable computer, the IBM 701, in the early 1950s. IBM has also been at the forefront of many pivotal technologies, including mainframe computers, which became central to large-scale enterprise computing. The System/360, introduced in 1964, revolutionized the industry by offering a compatible range of computers that could run the same software, a concept that helped define the standardization of computer systems.

IBM’s contributions to artificial intelligence, particularly through its Watson platform, are another hallmark of its heritage. Watson gained international fame for its success on the quiz show Jeopardy! in 2011, showcasing advanced natural language processing capabilities and machine learning techniques. This technology has since found applications in various fields, from healthcare to finance, significantly transforming data analysis.

Another key characteristic of IBM is its focus on research and development. With an impressive portfolio of patents, IBM consistently ranks among the top patent holders annually. Their research endeavors have led to significant advancements in quantum computing, with initiatives like the IBM Quantum Experience making quantum technologies accessible to developers and researchers.

Sustainability is also a priority for IBM, with programs aimed at promoting environmental responsibility. The company has committed to achieving net-zero greenhouse gas emissions by 2030, reflecting the growing importance of sustainability in technology practices.

In summary, IBM's heritage is characterized by a strong legacy of innovation, technological leadership, and a commitment to addressing contemporary challenges in business and society. From pioneering mainframe systems to leading the charge in AI and quantum computing, IBM continues to shape the future of technology while maintaining a visionary outlook towards a sustainable and inclusive digital world.
Top Page Image Contents