multicast minimum-ttl

Function

The multicast minimum-ttl command sets the minimum TTL value of multicast packets that an interface is allowed to send.

The undo multicast minimum-ttl command restores the default value.

By default, the minimum TTL value of multicast packets is 1.

Format

multicast minimum-ttl ttl-value

undo multicast minimum-ttl

Parameters

Parameter	Description	Value
ttl-value	Minimum TTL value of multicast packets on an interface.	The value is an integer that ranges from 1 to 255.

Parameter

Description

Value

ttl-value

Minimum TTL value of multicast packets on an interface.

The value is an integer that ranges from 1 to 255.

Views

100ge sub-interface view, 100GE interface view, 10GE sub-interface view, 10GE interface view, 200GE sub-interface view, 25GE sub-interface view, 25GE interface view, 400GE sub-interface view, 400GE interface view, 40GE sub-interface view, 40GE interface view, 50GE sub-interface view, 50GE interface view, Eth-Trunk sub-interface view, Eth-Trunk interface view, FlexE interface view, GE optical interface view, GE sub-interface view, GE interface view, GE electrical interface view, Global VE sub-interface view, Loopback interface view, MTI interface view, Mtunnel view, Tunnel interface view, VBDIF interface view, VE sub-interface view, VLANIF interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
mcast-base	write

Usage Guidelines

Usage Scenario

By setting the minimum TTL value of multicast packets on an interface, you can limit the transmission distance of multicast packets. If you do not want an interface to forward multicast packets, you can change the minimum TTL value set on the interface to a larger value.

When forwarding a packet (including the packet sent by the local Router) through an interface, the Router checks the TTL value of the packet:

If the TTL value (which is reduced by 1 by the local Router) is greater or equal to the minimum TTL value set on the interface, the packet is forwarded.
If the TTL value is smaller than the minimum TTL value set on the interface, the packet is discarded.

Prerequisites

The multicast routing-enable command is run in the public network instance view or VPN instance view.

Configuration Impact

If the multicast minimum-ttl command is run more than once, the latest configuration overrides the previous one.

Precautions

If the minimum TTL value is set to 255 on an interface, the interface does not forward any multicast packets.

This command applies only to the view of a tunnel interface with an encapsulation mode of GRE or TE.

Example

# Set the minimum TTL value of multicast packets that GE 0/1/0 is allowed to send to 8.

<HUAWEI> system-view
[~HUAWEI] multicast routing-enable
[*HUAWEI] interface GigabitEthernet 0/1/0
[*HUAWEI-GigabitEthernet0/1/0] multicast minimum-ttl 8