IGMP Features Supported

The IGMP features that the system supports are basic IGMP functions, Router-Alert option, IGMP query controller, SSM mapping, limit on the number of IGMP group memberships, and filtering of IGMP Report messages based on source addresses.

Basic Functions of IGMP

The basic IGMP functions that the FW supports are as follows:

IGMPv1, IGMPv2, and IGMPv3 (the IGMP version can be configured)
Static IGMP
Limit on the range of multicast groups that an interface can join

Currently, IGMPv3 supported by the FW can process the packets that match the following situations:

The group address is within the SSM group address range.
The group address is within the ASM group address range, the mode of group record is MODE_IS_EXCLUDE or CHANGE_TO_EXCLUDE_MODE, and the source address list is null.

Packets that do not match these conditions are not processed.

Router-Alert

Through Router-Alert, IGMP sends the messages for the group that the local device does not join to the upper protocol for processing.

According to requirements, users can determine whether to set Router-Alert in IGMP packets to be sent, and whether to require that the received IGMP packets contain Router-Alert.

IGMP Query Controller

For IGMPv1, users can set the interval for sending general query messages and the robustness variable.

For IGMPv2, users can configure the interval for sending general query messages, robustness variables, the maximum response time of IGMP query packets, and IGMP fast leave.

For IGMPv3, users can configure the interval for sending general query messages, robustness variables, and the maximum response time of IGMP query packets.

SSM-Mapping

You can configure SSM mapping on FWs to provide SSM services for hosts that run IGMPv1 or IGMPv2.

Limiting the Number of IGMP Group Memberships

Limiting the total number of IGMP group memberships on a FW: The total number of IGMP group memberships created by the FW cannot exceed the limit value. When the total number of IGMP group memberships created by a FW reaches the limit value, no IGMP entry can be created.
Limiting the total number of IGMP group memberships in a single instance: The total number of IGMP group memberships related to an instance cannot exceed the limit value. When the total number of IGMP group memberships related to an instance reaches the limit value, no IGMP entry can be created.
Limiting the total number of IGMP group memberships on an interface: The total number of IGMP group memberships created on an interface cannot exceed the limit value. When the total number of IGMP group memberships created on an interface reaches the limit value, no IGMP entry can be created.

Source Address-based IGMP Report, Leave, or Query Message Filtering

A fixed or configurable ACL rule can be used to implement source address-based IGMP Report, Leave, or Query message filtering.