Internet Engineering Task Force (IETF) R. Housley
Request for Comments: 7249 Vigil Security
Category: Informational May 2014
ISSN: 2070-1721
Internet Numbers Registries
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RFC 7249 Internet Numbers Registries May 2014 1. IntroductionIn accordance with the IETF-IANA Memorandum of Understanding [RFC2860], RFC 7020 [RFC7020] provides information about the Internet Numbers Registry System and how it is used in the distribution of autonomous system (AS) numbers and globally unique unicast Internet Protocol (IP) address space.
2. Internet Numbers Registries
Three IANA registries are associated with the Internet Numbers Registry System: "Autonomous System (AS) Numbers", "IANA IPv4 Address Space Registry", and "IPv6 Global Unicast Address Assignments". However, in each case, there are special-purpose values, and those special-purpose values are outside the Internet Numbers Registry System.
2.1. Autonomous System Numbers
For historical reasons, there are 16-bit AS numbers and 32-bit AS numbers. However, the 16-bit AS numbers are really just zero through 65535 of the 32-bit AS number space.
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RFC 7249 Internet Numbers Registries May 2014 2.2. IPv4 AddressesThe allocation and registration functions for all non-reserved, globally unique unicast IPv4 addresses are handled by the Internet Numbers Registry System in accordance with policies developed by the RIRs in accordance with their processes.
2.3. IPv6 Addresses
The vast bulk of the IPv6 address space (approximately 7/8ths of the whole address space) is reserved by the IETF [RFC4291], with the expectation that further assignment of globally unique unicast address space will be made from this reserved space in accordance with future needs.
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RFC 7249 Internet Numbers Registries May 2014 3. IANA ConsiderationsIANA has created the "Special-Purpose AS Numbers" registry. Future additions to this registry can be made through "IETF Review" as defined in [RFC5226]. At this time, the special-purpose AS numbers are:
AS Numbers Reason for Reservation --------------------- ------------------------------------------- 0 Reserved by [AS0-PROCESS]23456 AS_TRANS; reserved by [RFC6793] 64496-64511 For documentation and sample code; reserved
4. Security Considerations
This document identifies the IANA registries that are part of the Internet Numbers Registry System at the time of publication. It does not change the security posture of the Internet in any way.5. References 5.1. Normative References[RFC2860] Carpenter, B., Baker, F., and M. Roberts, "Memorandum of
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RFC 7249 Internet Numbers Registries May 2014 5.2. Informative References[AS0-PROCESS]
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RFC 7249 Internet Numbers Registries May 2014
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