Johns Hopkins University Applied Physics Lab

brian@innovationslab.net

This document specifies revised IANA Considerations for the Internet Group Management Protocol and the Multicast Listener Discovery protocol. This document specifies the guidance provided to IANA to manage values associated with various fields within the protocol headers of the group management protocols. This document obsoletes RFC 3228 and unifies guidelines for IPv4 and IPv6 group management protocols.

The following sections describe the allocation guidelines associated with the specified fields within the Internet Group Management Protocol (IGMP) and the Multicast Listener Discovery (MLD) headers. Some of these registries were created previously, while others are created by this document. This document obsoletes and unifies guidelines for IPv4 and IPv6 group management protocols.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here.

The registration procedures used in this document are defined in .

The IGMP header contains the following fields that carry values assigned from IANA-managed name spaces: Type and Code. Code field values are defined relative to a specific Type value. created an IANA registry for the IGMP Type field. This document updates that registry in two ways: The registration procedure is changed to Standards Action. The reference for the registry is changed to this document. created an IANA registry for Code values for existing IGMP Type fields. The registration procedure for the existing registries is changed to Standards Action. The policy for assigning Code values for new IGMP Types MUST be defined in the document defining the new Type value.

As with IGMP, the MLD header also contains Type and Code fields. Assignment of those fields within the MLD header is defined in .

The IANA is requested to create a single registry for the bits in the Flags field of the Multicast Listener Query Message and the IGMPv3 Query Message . The format for the registry is:

The initial contents of this requested registry should contain the E-bit defined in . The assignment of new bit flags within the Flags field requires Standards Action.

The IANA is requested to create a single registry for the bits in the Flags field of the Multicast Listener Report Message and the IGMPv3 Report Message. The format for the registry is:

The initial contents of this requested registry should contain the E-bit defined in . The assignment of new bit flags within the Flags field require Standards Action.

Security analyzers such as firewalls and network intrusion detection monitors often rely on unambiguous interpretations of the fields described in this memo. As new values for the fields are assigned, existing security analyzers that do not understand the new values may fail, resulting in either loss of connectivity if the analyzer declines to forward the unrecognized traffic, or loss of security if it does forward the traffic and the new values are used as part of an attack. This vulnerability argues for high visibility (which the Standards Action process ensures) for the assignments whenever possible.

Bill Fenner was the author of RFC 3228, which forms a portion of the content contained herein.