Unix system administration handbook, 3rd edition [Book review]

explaining the politics of IP address delegation, from its historical beginnings to theageofICA”andARIN(the Assigned Registry of Internet Numbers). In particular, it is explained how, along a delegatidn process that eventually reaches the user’s company, the viewpoint and objectives of ISPs is different from that of IRs (Intemet Registries). ISPs favor routability and maximization of customer base for the given allotment of I P addresses. The objectives of ISPs are different from those of the user’s company, in that users do not wish for frequent renumbering unless a business case is made to favor such changes. We arewarned that the task of renumbering is not a light one, especially when one considers the potential for loss of income while the system is in an inconsistent or unstable state. The casual reader is convinced that the problem is indeed complex when more protocols and entities enter the picture, such as the Network Address Translation (NAT) , the DNS (for example, the need for quick secondary DNS updates), the renumbering of routers (which can have impact even to the authentication of dialup users), etc. A chapter deals with each foreseeable complication. Recognizing that the best transition approach for renumbering depends on the scale of the site, Dutcher provides three case studies, for small, medium and large networks respective. ly. The concluding chapter looks forward to the future when the adoption of IPv6 will contribute towards solving most of the IP address management problems. ‘