3Com Switch 4200G Configuration Guide

31
MULTICAST MAC ADDRESS ENTRY CONFIGURATION
Introduction In Layer 2 multicast, the system can add multicast forwarding entries dynamically
through Layer 2 multicast protocol. However, you can also statically bind a port to a
multicast address entry by configuring a multicast MAC address manually.
Generally, when receiving a multicast packet whose multicast address has not yet
been registered on the switch, the switch broadcasts the packet in the VLAN.
However, you can configure a static multicast MAC address entry to avoid this case.
Configuring a
Multicast MAC
Address Entry
Table 232 describes how to configure a multicast MAC address entry.
You can use the corresponding undo command to cancel the configuration.
CAUTION:
■ If the multicast MAC address entry you are creating already exists, the system gives
you a prompt.
■ The switch will not learn a manually added multicast MAC address by IGMP
Snooping. The undo mac-address multicast command can only remove
manually created multicast MAC address entries and cannot remove those learned
by the switch.
■ To add a port to a manually created multicast MAC address entry, first remove the
entry, and then re-create the entry and specify the port as the forward port of the
entry.
■ The system does not support the configuration of multicast MAC address on an
IRF port. If you do this, the system will give you a prompt that the multicast MAC
address configuration fails.
Table 232 Configure a multicast MAC address entry
Operation Command Description
Enter system view system-view —
Add a multicast MAC address
entry
mac-address multicast
mac-address interface
interface-list vlan vlan-id
Required
mac-address must be a
multicast MAC address.
vlan-id is the ID of the VLAN to
which the port belongs.
Enter Ethernet port view interface interface-type
interface-number
—
Add a multicast MAC address
entry.
mac-address multicast
mac-address vlan vlan-id
Optional
This command is used in
Ethernet port view. It has the
same effect as the above
mac-address multicast
interface vlan command used
in system view with the same
port specified.