
IGMP TYPE NUMBERS - per [RFC3228, BCP57]

(last updated 27 June 2005)

The Internet Group Message Protocol (IGMP) has many messages 
that are identified by a "type" field.

Note that the original definition of IGMP in [RFC1112] divided 
this field into two 4-byte values, "version" and "type".  This 
was decided to be too restrictive, so the fields were combined 
into a single 8-bit type space.

Type      Name                                    Reference
----      ----------------------                  ---------
0x11      IGMP Membership Query                   [RFC1112]
0x12      IGMPv1 Membership Report                [RFC1112]
0x13      DVMRP                                  [RFCDVMRP]
0x14      PIM version 1                             [PIMv1]
0x15      Cisco Trace Messages
0x16      IGMPv2 Membership Report                [RFC2236]
0x17      IGMPv2 Leave Group                      [RFC2236]
0x1e      Multicast Traceroute Response            [Fenner]
0x1f      Multicast Traceroute                     [Fenner]
0x22      IGMPv3 Membership Report                [RFC3376]
0x30      Multicast Router Advertisement          [RFC-ietf-magma-mrdisc-07.txt]
0x31      Multicast Router Solicitation           [RFC-ietf-magma-mrdisc-07.txt]
0x32      Multicast Router Termination            [RFC-ietf-magma-mrdisc-07.txt]
0xf0-0xff Reserved for experimentation     [RFC3228, BCP57]


Many of these IGMP types have a "code" field.  Here we list 
the types again with their assigned code fields.

Type      Name                                    Reference
----      -------------------------               ---------
0x11      IGMP Membership Query                   [RFC1112]

          Codes
              0  IGMP Version 1
          1-255  IGMP Version 2 or above Max Response Time

0x12      IGMPv1 Membership Report                [RFC1112]

0x13      DVMRP                                  [RFCDVMRP]

          Codes
              1  Probe
              2  Route Report
              3  Old Ask Neighbors
              4  Old Neighbors Reply
              5  Ask Neighbors
              6  Neighbors Reply
              7  Prune
              8  Graft
              9  Graft Ack

0x14      PIM version 1                             [PIMv1]

          Codes
              0  Query
              1  Register
              2  Register-Stop
              3  Join/Prune
              4  RP-Reachable
              5  Assert
              6  Graft
              7  Graft Ack
              8  Mode

0x16      IGMPv2 Membership Report                [RFC2236]

0x17      IGMPv2 Leave Group                      [RFC2236]

0x1e      Multicast Traceroute Response            [Fenner]

0x1f      Multicast Traceroute                     [Fenner]

0x22      IGMPv3 Membership Report                [RFC3376]

0xf0-0xff Reserved for experimentation     [RFC3228, BCP57]

REFERENCES
----------

[RFC1112]  Deering, S., "Host extensions for IP multicasting", RFC 1112,
           Stanford University, August 1989.

[RFC2236]  Fenner, W., "Internet Group Management Protocol, Version 2",
           RFC 2236, Xerox PARC, November 1997.

[PIMv1]   Estrin, D. et al, "Protocol Independent Multicast (PIM):
          Protocol Specification", no stable reference known,
          draft-ietf-idmr-pim-spec-01.ps, January 1995.

[RFCDVMRP] Pusateri, T.,  "DVMRP Version 3", work in progress,
          Juniper Networks, July? 2001.

[RFC3376]  Cain, B., S. Deering, B. Fenner, I. Kouvelas, A. Thyagarajan,
           "Internet Group Management Protocol, Version 3", RFC 3376,
           September 2002.

[RFC3228]  Fenner, W., "IANA Considerations for IGMP", RFC 3228, BCP 57,
[BCP57]    February 2002.

[RFC-ietf-magma-mrdisc-07.txt]
           B. Haberman and J. Martin, "Multicast Router Discovery", RFC XXXX,
           Month Year.

PEOPLE
------

[Fenner] Bill Fenner, <fenner&research.att.com>

(created 06 February 2002)

[]

