Renumbering Needs Work
RFC 1900
Document | Type |
RFC - Informational
(February 1996; No errata)
Was draft-iab-renum (individual)
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Authors | Yakov Rekhter , Brian Carpenter | ||
Last updated | 2013-03-02 | ||
Stream | Legacy | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | Legacy state | (None) | |
Consensus Boilerplate | Unknown | ||
RFC Editor Note | (None) | ||
IESG | IESG state | RFC 1900 (Informational) | |
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group B. Carpenter Request for Comments: 1900 Y. Rekhter Category: Informational IAB February 1996 Renumbering Needs Work Status of this Memo This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Abstract Renumbering, i.e., changes in the IP addressing information of various network components, is likely to become more and more widespread and common. The Internet Architecture Board (IAB) would like to stress the need to develop and deploy solutions that would facilitate such changes. Table of Contents 1. Motivation................................................... 1 2. DNS versus IP Addresses...................................... 2 3. Recommendations.............................................. 3 4. Security Considerations...................................... 4 Acknowledgements................................................ 4 Authors' Addresses.............................................. 4 1. Motivation Hosts in an IP network are identified by IP addresses, and the IP address prefixes of subnets are advertised by routing protocols. A change in such IP addressing information associated with a host or subnet is known as "renumbering". Renumbering may occur for a variety of reasons. For example, moving an IP host from one subnet to another requires changing the host's IP address. Physically splitting a subnet due to traffic overload may also require renumbering. A third example where renumbering may happen is when an organization changes its addressing plan. Such changes imply changing not only hosts' addresses, but subnet numbers as well. These are just three examples that illustrate possible scenarios where renumbering could occur. Carpenter & Rekhter Informational [Page 1] RFC 1900 Renumbering Needs Work February 1996 Increasingly, renumbering will be needed for organizations that require Internet-wide IP connectivity, but do not themselves provide a sufficient degree of address information aggregation. Unless and until viable alternatives are developed, extended deployment of Classless Inter-Domain Routing (CIDR) is vital to keep the Internet routing system alive and to maintain continuous uninterrupted growth of the Internet. With current IP technology, this requires such organizations to use addresses belonging to a single large block of address space, allocated to their current service provider which acts as an aggregator for these addresses. To contain the growth of routing information, whenever such an organization changes to a new service provider, the organization's addresses will have to change. Occasionally, service providers themselves may have to change to a new and larger block of address space. In either of these cases, to contain the growth of routing information, the organizations concerned would need to renumber their subnet(s) and host(s). If the organization does not renumber, then some of the potential consequences may include (a) limited (less than Internet-wide) IP connectivity, or (b) extra cost to offset the overhead associated with the organization's routing information that Internet Service Providers have to maintain, or both. Currently, renumbering is usually a costly, tedious and error-prone process. It normally requires the services of experts in the area and considerable advance planning. Tools to facilitate renumbering are few, not widely available, and not widely deployed. While a variety of ad hoc approaches to renumbering have been developed and used, the overall situation is far from satisfactory. There is little or no documentation that describes renumbering procedures. While renumbering occurs in various parts of the Internet, there is little or no documented experience sharing. 2. DNS versus IP Addresses Within the Internet architecture an individual host can be identified by the IP address(es) assigned to the network interface(s) on that host. The Domain Name System (DNS) provides a convenient way to associate legible names with IP addresses. The DNS name space is independent of the IP address space. DNS names are usually related to the ownership and function of the hosts, not to the mechanisms of addressing and routing. A change in DNS name may be a sign of a real change in function or ownership, whereas a change in IP address is a purely technical event. Expressing information in terms of Domain Names allows one to defer binding between a particular network entity and its IP address untilShow full document text