3Com 5500 SI - Switch - Stackable, Configuration Manual

Page: 330 / 686

330 C
HAPTER
18: M
ULTICAST
P
ROTOCOL
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 Interface view.
By default, the maximum number of IGMP groups on an interface is 1024.
If the number of IGMP groups on an interface has exceeded the specified value
during configuration, no IGMP group will be deleted.
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.
Configuring one interface of the router as multicast member can avoid such problem.
When the interface receives IGMP query packet, the router will respond, thus
ensuring that the network segment where the interface is connected can normally
receive multicast packets.
For a Switch 5500, you can configure a port in a VLAN interface to join a multicast
group.
Perform the following configuration in the corresponding view.
Table 331 Configuring interval for querying IGMP packets
Operation Command
Configure interval for querying IGMP
packets
igmp lastmember-queryinterval seconds
Restore the default query interval
undo igmp lastmember-queryinterval
Table 332 Configure the number of last member querying
Operation Command
Configure number of last member querying
igmp robust-count robust-value
Restore the default number of querying
undo igmp robust-count
Table 333 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