3Com 5500-SI Configuring Multicast VLAN

320 CHAPTER 18: MULTICAST PROTOCOL
Configuring Multicast
VLAN
In old multicast mode, when users in different VLANs order the same multicast group,
the multicast stream is copied to each of the VLANs. This mode wastes a lot of
bandwidth.
By configuring a multicast VLAN, adding switch ports to the multicast VLAN and
enabling IGMP Snooping, you can make users in different VLANs share the same
multicast VLAN. This saves bandwidth since multicast streams are transmitted only
within the multicast VLAN, and also guarantees security because the multicast VLAN
is isolated from user VLANs.
Multicast VLAN is mainly used in Layer 2 switching, but you must make corresponding
configuration on the Layer 3 switch.
Table317 describes the configuration tasks for multicast VLAN.
Configure the maximum
number of multicast groups
the port can join.
igmp-snooping group-limit [
vlan vlan-list |
overflow-replace ]
Required
By default, there is no limit on
the number of the multicast
groups the port can join.
Table316 Configure the maximum number of multicast groups on a port (continued)
Operation Command Description
Table317 Configure multicast VLAN on Layer 3 switch
Operation Command Description
Enter system view system-view —
Create a VLAN and enter the
VLAN view
vlan vlan-id vlan-id is a VLAN ID.
Exit the VLAN view quit —
Create a VLAN interface and
enter the VLAN interface view
interface vlan-interface
vlan-id
—
Enable IGMP igmp enable Required
Exit the VLAN interface view quit —
Enter the view of the Ethernet
port connected to the Layer 2
switch
interface interface-type
interface-num
—
Define the port as a trunk or
hybrid port
port link-type { trunk |
hybrid }Required
Set the VLAN IDs allowed to
pass through the Ethernet
port hybrid vlan vlan-id-list {
tagged | untagged }
Required
The multicast VLAN defined on
the Layer 2 switch must be
included and set as tagged.
port trunk pvid vlan vlan-id
Table318 Configure multicast VLAN on Layer 2 switch
Operation Command Description
Enter system view system-view —
Enable IGMP Snooping globally igmp-snooping enable Required
Enter VLAN view vlan vlan-id vlan-id is a VLAN ID.
Enable IGMP Snooping on the
VLAN
igmp-snooping enable Required