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Extended Assignments in 233/8 (RFC3138) Disclosure Number: IPCOM000005322D
Original Publication Date: 2001-Jun-01
Included in the Prior Art Database: 2001-Aug-21
Document File: 5 page(s) / 7K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

D. Meyer: AUTHOR


This memo provides describes the mapping of the GLOP addresses corresponding to the private AS space.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 52% of the total text.

Network Working Group D. Meyer Request for Comments: 3138 Sprint Category: Informational June 2001

Extended Assignments in 233/8

Status of this Memo

This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (2001). All Rights Reserved.


This memo provides describes the mapping of the GLOP addresses corresponding to the private AS space.

1. Introduction

RFC 2770 [RFC2770] describes an experimental policy for use of the class D address space using 233/8. The technique described there maps 16 bits of Autonomous System number (AS) into the middle two octets of 233/8 to yield a /24. While this technique has been successful, the assignments are inefficient in those cases in which a /24 is too small or the user doesn't have its own AS.

RFC 1930 [RFC1930] defines the private AS space to be 64512 through 65535. This memo expands on RFC 2770 to allow routing registries to assign multicast addresses from the GLOP space corresponding to the RFC 1930 private AS space. This space will be referred to as the EGLOP (Extended GLOP) address space.

This memo is a product of the Multicast Deployment Working Group (MBONED) in the Operations and Management Area of the Internet Engineering Task Force. Submit comments to or the authors.

The terms "Specification Required", "Expert Review", "IESG Approval", "IETF Consensus", and "Standards Action", are used in this memo to refer to the processes described in [RFC2434]. The keywords MUST, MUST NOT, MAY, OPTIONAL, REQUIRED, RECOMMENDED, SHALL, SHALL NOT, SHOULD, SHOULD NOT are to be interpreted as defined in RFC 2119 [RFC2119].

Meyer Informational [Page 1]

RFC 3138 Extended Assignments in 233/8 June 2001

2. Overview defines a mechanism for assignment of multicast addresses that are generally for use in network control applications. It is envisioned that those addresses assigned from the EGLOP space ( will be used by applications that cannot use Administratively Scoped Addressing [RFC2365], GLOP Addressing [RFC2770], or Source Specific Multicast (Source Specific Multicast, or SSM, is an extension of IP Multicast in which traffic is forwarded to receivers from only those multicast sources for which the receivers have explicitly expressed interest, and is primarily targeted at one-to-many (broadcast) applications).

3. Assignment Criteria

Globally scoped IPv4 multicast addresses in the EGLOP space are assigned by a Regional Registry (RIR). An applicant MUST, as per [IANA], show that the request cannot be satisfied using Administratively Scoped addressing [RFC2365], GLOP addressing [RFC2770], or SSM. The fine-grained assignment policy is left to the assigning RIR.

4. Security Considerations

The assignment scheme described in this document does not effect the security properties of the the single...