Configuring IGMP parameters on a VLAN

Configure IGMP for each interface to enable the interface to perform multicasting operations.

Procedure

  1. In the navigation pane, expand the following folders: Configuration > VLAN.
  2. Click VLANs.
  3. Click the Basic tab.
  4. Select a VLAN.
  5. Click IP.
  6. Select IGMP.
  7. Configure the relevant variables.
    Note

    Note

    When you configure the following IGMP parameters on the DvR Controllers in a DvR domain, the configuration is automatically pushed to the Leaf nodes within the domain.

    • Version

    • QueryInterval

    • QueryMaxResponseTime

    • Robustness

    • LastMembQueryIntvl

    • CompatibilityModeEnable

    Configuration of IGMP snooping is not supported on DvR enabled Layer 2 VSNs.

  8. Click Apply.

IGMP field descriptions

Use the data in the following table to use the IGMP tab.

Name

Description

QueryInterval

Configures the frequency (in seconds) at which the IGMP host query packets transmit on the interface. The range is from 1–65535 and the default is 125.

QueryMaxResponseTime

Configures the maximum response time (in tenths of a second) advertised in IGMPv2 general queries on this interface. You cannot configure this value for IGMPv1.

Smaller values allow a router to prune groups faster. The range is from 0–255 and the default is 100 tenths of a second (equal to 10 seconds.)

Important:

You must configure this value lower than the QueryInterval.

Robustness

Configure this parameter to tune for the expected packet loss of a network. This value is equal to the number of expected query packet losses for each serial query interval, plus 1. If you expect the network to lose query packets, increase the robustness value.

The range is from 2–255 and the default is 2. The default value of 2 means that the switch drops one query for each query interval without the querier aging out.

LastMembQueryIntvl

Configures the maximum response time (in tenths of a second) inserted into group-specific queries sent in response to leave group messages. This value is also the time between group-specific query messages. You cannot configure this value for IGMPv1.

Decreasing the value reduces the time to detect the loss of the last member of a group. The range is from 0–255 and the default is 10 tenths of a second. Configure this parameter to values greater than 3. If you do not require a fast leave process, use values greater than 10. (The value 3 is equal to 0.3 seconds, and 10 is equal to 1 second.)

SnoopEnable

Enables snoop on the interface. The default is disabled.

SsmSnoopEnable

Enables SSM snoop. The default is disabled.

ProxySnoopEnable

Enables proxy snoop on the interface. The default is disabled.

Version

Configures the version of IGMP (1, 2, or 3) that you want to use on this interface. For IGMP to function correctly, all routers on a LAN must use the same version. The default is version 2.

FastLeaveEnable

Enables or disables fast leave on the interface.

StreamLimitEnable

Enables or disables stream limitation on this VLAN.

Maximum Number Of Stream

Configures the maximum number of streams allowed on this VLAN. The range is from 0–65535 and the default is 4.

Current Number Of Stream

Displays the current number of streams. This value is a read-only value.

FastLeavePortMembers

Lists ports that are enabled for fast leave.

SnoopMRouterPorts

Shows the configuration of ports as multicast router ports. Such ports attach to a multicast router, and forward multicast data and group reports to the router.

Important:

Configure this field only if you use multiple multicast routers that do not attach to one another, but attach to the VLAN (technically, an invalid configuration). If multicast routers use a route between them (the valid configuration) and you configure this variable, a multicast loop forms.

RouterAlertEnable

Instructs the router to ignore IGMP packets that do not contain the router alert IP option. If you disable this variable (default configuration), the router processes IGMP packets regardless of the status of the router alert IP option.

To maximize network performance, configure this parameter according to the version of IGMP currently in use:

  • IGMPv1—Disable

  • IGMPv2—Enable

  • IGMPv3—Enable

DynamicDowngradeEnable

Configures if the switch downgrades the version of IGMP to handle older query messages. If the switch downgrades, the host with IGMPv3 only capability does not work. If you do not configure the switch to downgrade the version of IGMP, the switch logs a warning. The default value is selected (enabled), which means the switch downgrades to the oldest version of IGMP on the network.

CompatibilityModeEnable

Enables or disables v2-v3 compatibility mode. The default value is clear (disabled), which means IGMPv3 is not compatible with IGMPv2.

ExplicitHostTrackingEnable

Enables or disables IGMPv3 to track hosts per channel or group. The default is disabled. You must select this field if you want to use fast leave for IGMPv3.

SnoopQuerierEnable

Enables snoop querier. The default is disabled.

When you enable IGMP Layer 2 Querier, Layer 2 switches in your network can snoop IGMP control packets exchanged with downstream hosts and upstream routers. The Layer 2 switches then generate the Layer 2 MAC forwarding table, used for switching sessions and multicast traffic regulation, and provide the recurring queries required to maintain IGMP groups.

Enable Layer 2 Querier on only one node in the VLAN.

SnoopQuerierAddr

Specifies the pseudo IP address of the IGMP snoop querier. The default IP address is 0.0.0.0.
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