Assigning Ports to Multicast Services
Multicast filtering can be dynamically configured using IGMP Snooping and IGMP
Query messages as described in “Configuring IGMP Snooping and Query
Parameters” on page 15-3. For certain applications that require tighter control, you
may need to statically configure a multicast service on the switch. First add all the
ports attached to participating hosts to a common VLAN, and then assign t he
multicast service to that VLAN group.
Command Usage
• Static multicast addresses are never aged out.
• When a multicast address is assigned to an inte rface i n a specific VLAN, the
corresponding traffic can only be forwarded to ports within that VLAN .
Command Attribute
• Interface – Activates the Port or Trunk scroll down list.
• VLAN ID – Selects the VLAN to propagat e all multica st traffic coming from the
attached multicast router/switch. (Range: 1-4093)
• Multicast IP – The IP add ress for a spe cific multicast ser vice
• Unit – Stack unit. (Range: 1-8)
• Port or Trunk – Spec ifies the in terfac e att ached t o a m ulti cast r oute r/switch .
Web
– Click IGMP Snooping, IGMP Member Port Table. Specify the interface
attached to a multicast service (via an IGMP-enabled switch or multic ast router) ,
indicate the VLAN that will propagate the multicast service, specify the mult icast IP
address, and click Add. After you have completed adding ports t o the membe r list,
click Apply.
Figure 15-5 IGMP Member Port Table
CLI – This example assigns a multicast address to VLAN 1, and then d ispl ays all the
known multicast services supported on VLAN 1.
Console(config)#ip igmp snooping vlan 1 static 224.1.1.12
ethernet 1/12
Console(config)#exit
Console#show mac-address-table multicast vlan 1
VLAN M'cast IP addr. Member ports Type
---- --------------- ------------ -------
1 224.1.1.12 Eth1/12 USER
1 224.1.2.3
E
th1/12
I
GMP
37-2
37-4

15-9

Layer 2 IGMP (Snooping and Query)

15