3Com Switch 8800 Configuration Guide
Chapter 27 IGMP Configuration
27-6
maximum response time. When any timer becomes 0, the host will send the
membership report message of the multicast group.
Setting the maximum response time reasonably can enable the host to respond to
query messages quickly. In this case, the router can fast master the existing status of
the members of the multicast group.
Perform the following configuration in VLAN interface view.
Table 27-7
Configuring the maximum response time for IGMP query message
Operation
Command
Configure the maximum response time for IGMP
query message
igmp max-response-time
seconds
Restore the maximum query response time to the
default value
undo igmp
max-response-time
The smaller the maximum query response time value, the faster the router prunes
groups. The actual response time is a random value in the range from 1 to 25 seconds.
By default, the maximum query response time is 10 seconds.
27.2.8 Configuring the limit of IGMP groups on an interface
If there is no limit to the number of IGMP groups added on a router interface or a router,
the router memory may be exhausted, which may cause router failure.
You can set number limit for the IGMP groups added on the interface, but not the
number limit for the IGMP groups added in the router, which is defined by the system.
Perform the following configuration in VLAN interface view.
Table 27-8
Configuring the limit of IGMP groups on an interface
Operation
Command
Configure the limit of IGMP groups on an interface
igmp group-limit
limit
Restore the limit of IGMP groups on an interface to
the default value
undo igmp group-limit
By default, the maximum number of IGMP groups on an interface is 512.
If the number of IGMP groups on an interface has exceeded the specified value during
configuration, the existing IGMP groups will not be deleted.
27.2.9 Configuring a Router to Join Specified Multicast Group
Usually, the host operating IGMP will respond to IGMP query packet of the multicast
router. In case of response failure, the multicast router will consider that there is no
multicast member on this network segment and will cancel the corresponding path.