RFC 3228 (rfc3228) - Page 2 of 4
IANA Considerations for IPv4 Internet Group Management Protocol (IGMP)
Alternative Format: Original Text Document
RFC 3228 IANA Considerations for IPv4 IGMP February 2002 2. IANA Considerations for fields in the IPv4 IGMP header The IPv4 IGMP header [1] 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. Values for the IPv4 IGMP Type fields are allocated using an IESG Approval or Standards Action processes. Code Values for existing IPv4 IGMP Type fields are allocated using IESG Approval or Standards Action processes. The policy for assigning Code values for new IPv4 IGMP Types should be defined in the document defining the new Type value. 3. Assignments for testing and experimentation Instead of suggesting temporary assignments as in [3], this document follows the lead of [4] and assigns a range of values for experimental use. The IGMP Code values 240-255 inclusive (0xf0 - 0xff) are reserved for protocol testing and experimentation. Systems should silently ignore IGMP messages with unknown Code values. 4. Security Considerations 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 and IETF Consensus processes ensure) for the assignments whenever possible. 5. Normative References [1] Fenner, W., "Internet Group Management Protocol, Version 2", RFC 2236, November 1997. [2] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998. Fenner Best Current Practice
