igmp ttl-check

Function

The igmp ttl-check command enables the device to check the TTL values in received IGMP Report, Leave, and Query messages on a specific interface.

The undo igmp ttl-check command restores the default configuration.

By default, the device does not check the TTL values in received IGMP Report, Leave, and Query messages on an interface.

Format

igmp ttl-check

undo igmp ttl-check

Parameters

None

Views

Interface view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

To protect a device against IGMP message attacks, run the igmp ttl-check command to enable the device to check the TTL values in received IGMP Report, Leave, and Query messages on a specific interface and discard such a message if its TTL value is not 1.

The igmp ttl-check command provides the same function as the ttl-check command run in the IGMP view, except that the ttl-check command configuration takes effect for all interfaces in the instance.

Configuration Impact

If both the igmp ttl-check and ttl-check commands are run, the igmp ttl-check configuration in the interface view takes precedence over the ttl-check configuration in the IGMP view.

Example

# Enable the device to check the TTL values in received IGMP Report, Leave, and Query messages on a specific interface.

<sysname> system-view
[sysname] interface GigabitEthernet 0/0/0
[sysname-GigabitEthernet0/0/0] igmp ttl-check