HP VPN Firewall Appliances Network Management Configuration Guide

584
Configuration prerequisites
Before adjusting IGMP performance, complete the following tasks:
• Configure any unicast routing protocol so that all devices in the domain are interoperable at the
network layer.
• Configure basic IGMP functions.
• Determine the startup query interval.
• Determine the startup query count.
• Determine the IGMP general query interval.
• Determine the IGMP querier's robustness variable.
• Determine the maximum response time for IGMP general queries.
• Determine the IGMP last-member query interval.
• Determine the other querier present interval.
Configuring Router-Alert option handling methods
IGMP queries include group-specific queries and group-and-source-specific queries. Multicast groups
change dynamically, so a device cannot maintain the information for all multicast sources and groups.
For this reason, when an IGMP router receives a multicast packet but cannot locate the outgoing interface
for the destination multicast group, it must use the Router-Alert option to pass the multicast packet to the
upper-layer protocol for processing. For more information about the Router-Alert option, see RFC 2113.
An IGMP message is processed differently depending on whether it carries the Router-Alert option in the
IP header:
• For compatibility, the device by default ignores the Router-Alert option and processes all received
IGMP messages, no matter whether the IGMP messages carry the Router-Alert option.
• To enhance device performance, avoid unnecessary costs, and ensure protocol security, configure
the device to discard IGMP messages that do not carry the Router-Alert option.
To configure Router-Alert option handling methods globally:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter public network IGMP view.
igmp N/A
3. Configure the router to discard any
IGMP message that does not carry the
Router-Alert option.
require-router-alert
By default, the device does not
check the Router-Alert option.
4. Enable insertion of the Router-Alert
option into IGMP messages.
send-router-alert
By default, IGMP messages carry
the Router-Alert option.
To configure Router-Alert option handling methods on an interface:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter interface view.
interface interface-type
interface-number
N/A