146 CHAPTER 6: MULTICAST PROTOCOL
Configure Switch C:
1 Enable PIM-SM.
[SW7750]multicast routing-enable
[SW7750]vlan 10
[SW7750-vlan10]port Ethernet 1/0/2 to Ethernet 1/0/3
[SW7750-vlan10]quit
[SW7750]pim
[SW7750-pim]interface vlan-interface 10
[SW7750-vlan-interface10]pim sm
[SW7750-vlan-interface10]quit
[SW7750]vlan 11
[SW7750-vlan11]port Ethernet 1/0/4 to Ethernet 1/0/5
[SW7750-vlan11]quit
[SW7750]pim
[SW7750-pim]interface vlan-interface 11
[SW7750-vlan-interface11]pim sm
[SW7750-vlan-interface11]quit
[SW7750]vlan 12
[SW7750-vlan12]port Ethernet 1/0/6 to Ethernet 1/0/7
[SW7750-vlan12]quit
[SW7750]pim
[SW7750-pim]interface vlan-interface 12
[SW7750-vlan-interface12]pim sm
[SW7750-vlan-interface12]quit
GMRP GMRP (GARP Multicast Registration Protocol), based on GARP, is used for
maintaining dynamic multicast registration information. All the switches
supporting GMRP can receive multicast registration information from other
switches, and dynamically update local multicast registration information. Local
multicast registration information can be transmitted to other switches. This
information switching mechanism keeps consistency of multicast information
maintained by every GMRP-supporting device in the same switching network.
A host transmits GMRP Join message. After receiving the message, the switch
adds the port to the multicast group, and broadcasts the message throughout the
VLAN; thereby the multicast source in the VLAN knows the multicast member.
When the multicast source sends packets to its group, the switch only forwards
the packets to the ports connected to members, thereby implementing the Layer 2
multicast in VLAN.
The multicast information transmitted by GMRP includes, local static multicast
registration information configured manually, and the multicast registration
information dynamically registered by other switches.
Configuring GMRP The main tasks in a GMRP configuration are described in the following sections:
■ Enable/Disable GMRP Globally
■ Enabling/Disabling GMRP on the Port
■ Displaying and Debugging GMRP
In the configuration process, GMRP must be enabled globally before it is enabled
on the port.