A host sends an IGMP Leave message to stop receiving multicast traffic. After receiving the Leave message, the router sends a query to the local subnet to determine whether any group members remain, sending the message to all hosts on the subnet at the multicast All-Hosts address (224.0.0.1). If a host responds, the router continues to send to the group. If no host responds, the router removes the multicast group from its forwarding list and stops sending to the group.
Note
Leave Group synchronization and maximum response times are used during Leave Group procedures.| Packets | Description |
|---|---|
| RD (8 Octets) | |
| Ethernet Segment Identifier (10 octets) | 0 if (S,G) / (*,G) is learned on CEP |
| Ethernet Tag ID (4 octets) | 0 or optionally, set to the VLAN ID over which the multicast route is learned |
| Multicast Source Length (1 octet) | 32 for IPv4 address and 0 for wildcard address (*) |
| Multicast Source Address (variable) | IP address of multicast source |
| Multicast Group Length (1 octet) | 32 for IPv4 address |
| Multicast Group Address (variable) | IP address of multicast group |
| Originator Router Length (1 octet) | 32 for IPv4 address |
| Originator Router Address (variable) | The IP address of the originating router |
| Leave Group Synchronization # (4 octets) | Leave group synchronization |
| Maximum Response Time (1 octet) | The maximum response time |
| Flags (1 octets) (optional) | The flag fields are defined in the following table |
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|
| Reserved | Reserved | Reserved | Reserved | IE | V3 | V2 | V1 |
| Bit 4: (S, G) information carries the route-type of Include Group (bit value 0) or Exclude Group (bit value 1). The Exclude Group is ignored if bit 5 is set for IGMP v2, IGMP v1. | Bit 5: support for IGMP v3 | Bit 6: support for IGMP v2 | Bit 7: support for IGMP v1 | ||||
| Bits 0, 1, 2, and 3 are reserved and used. | |||||||