3com 5500-SI Manual Do Utilizador
IGMP Snooping 317
Configuring IGMP
Snooping
IGMP Snooping configuration includes:
■
■
■
■
Of the above configuration tasks, enabling IGMP Snooping is required, while others
are optional.
are optional.
Enabling/Disabling IGMP Snooping
Use the commands in Table 310 to enable/disable IGMP Snooping on Layer 2. First
enable IGMP Snooping globally in System View, and then enable IGMP Snooping of
the corresponding VLAN in VLAN View.
enable IGMP Snooping globally in System View, and then enable IGMP Snooping of
the corresponding VLAN in VLAN View.
Perform the following configuration in System View and VLAN View.
Although layer 2 and layer 3 multicast protocols can run together, they cannot run on
the same VLAN or its corresponding VLAN interface at the same time. For example, if
the layer 2 multicast protocol is enabled on a VLAN, then the layer 3 multicast
protocol cannot operate on this VLAN, and vice-versa.
the same VLAN or its corresponding VLAN interface at the same time. For example, if
the layer 2 multicast protocol is enabled on a VLAN, then the layer 3 multicast
protocol cannot operate on this VLAN, and vice-versa.
IGMP Snooping functions only when it is enabled both in System View and in VLAN
View.
View.
By default, IGMP Snooping is disabled.
Configuring Router Port Aging Time
Use the commands in Table 311 to manually configure the router port aging time. If
the switch has not received a general query message from the router before the
router port is aged, the switch will remove the port from the MAC multicast group.
the switch has not received a general query message from the router before the
router port is aged, the switch will remove the port from the MAC multicast group.
IGMP leave message
Transmitted from the multicast group member to the multicast
router, to notify that a host has left the multicast group. The
Switch 5500 transmits the specific query message, concerning
the group, to the port that received the message in an effort to
check if the host still has other members of this group, and then
starts a maximum response timer. If the switch has not received
any report message from the multicast group, the port will be
removed from the corresponding MAC multicast group. If the
MAC multicast group does not have any member, the switch
will notify the multicast router to remove it from the multicast
tree.
router, to notify that a host has left the multicast group. The
Switch 5500 transmits the specific query message, concerning
the group, to the port that received the message in an effort to
check if the host still has other members of this group, and then
starts a maximum response timer. If the switch has not received
any report message from the multicast group, the port will be
removed from the corresponding MAC multicast group. If the
MAC multicast group does not have any member, the switch
will notify the multicast router to remove it from the multicast
tree.
Table 309 IGMP Snooping Terminology (continued)
Term
Meaning
Table 310 Enabling/Disabling IGMP Snooping
Operation
Command
Enable/disable IGMP Snooping
igmp-snooping { enable | disable }