Internet Group Management Protocol (IGMP) Type Numbers
2002-02-06
2022-08-03
The Internet Group Message Protocol (IGMP) has many messages
that are identified by a "type" field.
Note that the original definition of IGMP in divided
this field into two 4-bit values, "version" and "type". This
was decided to be too restrictive, so the fields were combined
into a single 8-bit type space.
IGMP Type Numbers
IESG Approval or Standards Action
0x00
Reserved
0x01-0x08
Reserved (Obsolete)
0x09-0x10
Unassigned
0x11
IGMP Membership Query
0x12
IGMPv1 Membership Report
0x13
DVMRP
0x14
PIM version 1
0x15
Cisco Trace Messages
0x16
IGMPv2 Membership Report
0x17
IGMPv2 Leave Group
0x1e
Multicast Traceroute Response
0x1f
Multicast Traceroute
0x22
IGMPv3 Membership Report
0x30
Multicast Router Advertisement
0x31
Multicast Router Solicitation
0x32
Multicast Router Termination
0xf0-0xff
Reserved for experimentation
"Code" Fields
IESG Approval or Standards Action
Many of these IGMP types have a "code" field. Here we list
the types again with their assigned code fields.
Type 0x11 - IGMP Membership Query
0
IGMP Version 1
1-255
IGMP Version 2 or above Max Response Time
Type 0x12 - IGMPv1 Membership Report
Type 0x13 - DVMRP
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
Type 0x14 - PIM version 1
0
Query
1
Register
2
Register-Stop
3
Join/Prune
4
RP-Reachable
5
Assert
6
Graft
7
Graft Ack
8
Mode
Type 0x16 - IGMPv2 Membership Report
Type 0x17 - IGMPv2 Leave Group
Type 0x1e - Multicast Traceroute Response
Type 0x1f - Multicast Traceroute
Type 0x22 - IGMPv3 Membership Report
Type 0xf0-0xff - Reserved for experimentation
IGMP/MLD Extension Types
0-65533
IETF Review
65534-65535
Experimental Use
0
variable
No-op
1-65533
Unassigned
65534-65535
variable
Reserved for Experimental Use
Bill Fenner
mailto:fenner&research.att.com