9. GLOP Block (233/8)

Addresses in the GLOP Block are globally-scoped, statically-assigned addresses. The assignment is made, for a domain with a 16-bit Autonomous System Number (ASN), by mapping a domain's autonomous system number, expressed in octets as X.Y, into the middle two octets of the GLOP Block, yielding an assignment of 233.X.Y.0/24. The mapping and assignment is defined in [RFC3180]. Domains with a 32-bit ASN MAY apply for space in AD-HOC Block III, or consider using IPv6 multicast addresses.

9.1. Assignment Guidelines

Because addresses in the GLOP Block are algorithmically pre-assigned, no IANA assignment policy is required.

9.2. AD-HOC Block III

[RFC3138] delegated to the RIRs the assignment of the GLOP sub-block (233.252.0.0 - 233.255.255.255) mapped by the private Autonomous System (AS) space (64512-65534) and the IANA reserved ASN 65535 [RFC1930]. This space was known as Extended GLOP (EGLOP). RFC 3138 should not have asked the RIRs to develop policies for the EGLOP space because [RFC2860] reserves that to the IETF. It is important to make this space available for use by network operators, and it is therefore appropriate to obsolete RFC 3138 and classify this address range as available for AD-HOC assignment as per the guidelines in section 6.

The first /24 in this range, 233.252.0.0/24, is assigned as "MCAST-TEST-NET" for use in documentation and example code. 233.252.0.0/24 SHOULD be used in conjunction with the [RFC2606] domain names example.com or example.net in vendor and protocol documentation. Addresses within 233.252.0.0/24 MUST NOT appear on the public Internet.