Network Working Group D. Meyer
Request for Comments: 3138 Sprint
Category: Informational June 2001
Extended Assignments in 233/8
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.
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RFC 3138 Extended Assignments in 233/8 June 2001 2. Overviewhttp://www.iana.org/assignments/multicast-addresses 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 (233.252.0.0 - 233.255.255.255) 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 source or any source multicast service models.
5. Acknowledgments
Kurt Kayser, Mirjam Kuehne, Michelle Schipper and Randy Bush provided many insightful comments on earlier versions of this document.
6. Author's Address
David Meyer Sprint 12502 Sunrise Valley Dr Reston VA, 20191
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RFC 3138 Extended Assignments in 233/8 June 2001 7. References [IANA] http://www.iana.org/assignments/multicast-addresses[RFC1930] Hawkinson J. and T. Bates, "Guidelines for
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RFC 3138 Extended Assignments in 233/8 June 2001
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