3Com Switch 8800 Advanced Software V5 Configuration Guide

Adjusting MLD Performance 643
By default, in consideration of compatibility, the device does not check the
Router-Alert option, that is, it processes all received MLD messages. In this case,
the device passes MLD messages to the upper layer protocol for processing, no
matter whether the MLD messages contain the Router-Alert option.
To enhance the device performance, avoid unnecessary costs, and ensure the
protocol security, you can configure the device to discard MLD messages without
the Router-Alert option. In this case, when the device receives an MLD message, it
checks it for the Router-Alert option, and discards it if it does not carry the
Router-Alert option.
Configure the Router-Alert option for MLD messages globally
Follow these steps to configure the Router-Alert option for MLD messages
globally:
Configure the Router-Alert option on an interface
Follow these steps to configure the Router-Alert option on an interface:
Configuring MLD Timers The MLD querier periodically sends MLD general query messages to decide
whether any IPv6 multicast group member exists on the network. You can modify
the query interval based on the actual condition of the network.
Upon receiving an MLD query (general query or multicast-address-specific query)
message, a host starts a timers for each IPv6 multicast group it has joined. The
timer is initialized to a random value in the range of 0 to the maximum response
delay (the host obtains the maximum response delay from the Maximum Response
Delay field in the MLD query message it received). When the timer value drops to
To do... Use the command... Remarks
Enter system view system-view -
Enter MLD view mld -
Configure the interface to
discard any MLD message
without the Router-Alert
option
require-router-alert Optional
By default, the device does
not check MLD messages for
the Router-Alert option.
Enable the insertion of the
Router-Alert option into MLD
messages
send-router-alert Optional
By default, MLD messages
carry the Router-Alert option.
To do... Use the command... Remarks
Enter system view system-view -
Enter VLAN interface view interface interface-type
interface-number
-
Configure the interface to
discard any MLD message
without the Router-Alert
option
mld require-router-alert Optional
By default, the device does
not check MLD messages for
the Router-Alert option.
Enable the insertion of the
Router-Alert option into MLD
messages
mld send-router-alert Optional
By default, MLD messages
carry the Router-Alert option.