Implications of Various Address Allocation Policies for Internet Routing
RFC 2008
Document | Type |
RFC - Best Current Practice
(October 1996; No errata)
Also known as BCP 7
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Authors | Yakov Rekhter , Tony Li | ||
Last updated | 2013-03-02 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 2008 (Best Current Practice) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group Y. Rekhter Request for Comments: 2008 T. Li BCP: 7 Cisco Systems Category: Best Current Practice October 1996 Implications of Various Address Allocation Policies for Internet Routing Status of this Memo This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. Distribution of this memo is unlimited. IESG Note: The addressing constraints described in this document are largely the result of the interaction of existing router technology, address assignment, and architectural history. After extensive review and discussion, the authors of this document, the IETF working group that reviewed it, and the IESG have concluded that there are no other currently deployable technologies available to overcome these limitations. In the event that routing or router technology develops to the point that adequate routing aggregation can be achieved by other means or that routers can deal with larger routing and more dynamic tables, it may be appropriate to review these constraints. 1 Abstract IP unicast address allocation and management are essential operational functions for the Public Internet. The exact policies for IP unicast address allocation and management continue to be the subject of many discussions. Such discussions cannot be pursued in a vacuum - the participants must understand the technical issues and implications associated with various address allocation and management policies. The purpose of this document is to articulate certain relevant fundamental technical issues that must be considered in formulating unicast address allocation and management policies for the Public Internet, and to provide recommendations with respect to these policies. The major focus of this document is on two possible policies, "address ownership" and "address lending," and the technical implications of these policies for the Public Internet. For the organizations that could provide reachability to a sufficiently large Rekhter & Li Best Current Practice [Page 1] RFC 2008 October 1996 fraction of the total destinations in the Internet, and could express such reachability through a single IP address prefix the document suggests to use the "address ownership" policy. However, applying the "address ownership" policy to every individual site or organization that connects to the Internet results in a non-scalable routing. Consequently, this document also recomments that the "address lending" policy should be formally added to the set of address allocation policies in the Public Internet. The document also recommends that organizations that do not provide a sufficient degree of routing information aggregation, but wish to obtain access to the Internet routing services should be strongly encouraged to use this policy to gain access to the services. 2 On the intrinsic value of IP addresses Syntactically, the set of IPv4 unicast addresses is the (finite) set of integers in the range 0x00000000 - 0xDFFFFFFF. IP addresses are used for Network Layer (IP) routing. An IP address is the sole piece of information about the node injected into the routing system. The notable semantics of an IP unicast address is its ability to interact with the Public Internet routing service and thereby exchange data with the remainder of the Internet. In other words, for the Public Internet, it is the reachability of an IP address that gives it an intrinsic value. Observe, however, that IP addresses are used outside of the Public Internet. This document does not cover the value of addresses in other than the Public Internet context. The above implies that in the Public Internet it is the service environment (the Internet) and its continued operation, including its routing system, which gives an IP address its intrinsic value, rather than the inverse. Consequently, if the Public Internet routing system ceases to be operational, the service disappears, and the addresses cease to have any functional value in the Internet. At this point, for the Public Internet, all address allocation and management policies, including existing policies, are rendered meaningless. 3 Hierarchical routing and its implication on address allocation Hierarchical routing [Kleinrock 77] is a mechanism that improves the scaling properties of a routing system. It is the only proven mechanism for scaling routing to the current size of the Internet. Hierarchical routing requires that addresses be assigned to reflectShow full document text