PLANET XGS3-24042 - Manual (Page 431)

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Source Specific Multicast (PIM-SSM) is a new kind of multicast service protocol. With PIM-SSM, a multicast
session is distinguished by the multicast group address and multicast source address. In SSM, hosts can be
added into the multicast group manually and efficiently like the traditional PIM-SM, but leave out the shared
tree and RP management in PIM-SM. In SSM, SPT tree will be constructed with (S, G). G for the multicast
group address and S for the source address of the multicast which sends datagram to G. (S, G) in a pair is
named as a channel of SSM. SSM serves best for the application of multicast service which is from one
station to many ones, for example, the network sports video channel, and the news channel. By default, the
multicast group address of SSM is limited between 232.0.0.0 and 232.255.255.255. However this address
range can be extended according to actual situations.
48.6.2 PIM-SSM Configuration Task List
Command Explanation
Global Configuration Mode
ip multicast ssm {default|range
<access-list-number >}
no ip multicast ssm
To configure the address range for pim-ssm. The
no form command will disable the configuration.
48.6.3 PIM-SSM Configuration Examples
As the figure shows, ethernet interfaces from SwitchA, SwitchB, SwitchC, and SwitchD are configured to be in
separate VLANs. And PIM-SSM is enabled globally by enabling the PIM-SM or PIM-DM protocol on the VLAN
interfaces. Take PIM-SM for example.
Figure 48-7 PIM-SSM typical environment
Configurations of SwitchA, SwitchB, SwitchC, and SwitchD are shown as below.
(1) Configuration of Switch A