Contemporary Control Systems Compact Managed Switches Software Manual for Console Access - Manual (Page 25)

TD020850-0MG
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4.3.6.1 Configure Multicast Filtering Table
A multicast message is one destined for two or more Ethernet devices. By default, the
switch transmits such a message over all of its ports. However, the switch can filter up
to ten multicast addresses so that messages sent to these addresses will only exit the
switch via certain designated ports. The switch also supports IGMP Snooping which
allows automatic filtering of multicast messages for devices that support multicasting as
described in Section 4.2.1.12.
For an 8-port switch, these settings are illustrated in Figure 17. In this screen the user
must enter the multicast MAC Address to represent each multicast group, the Priority
of those messages and the Ports that will carry messages to that group. By default,
each address is assigned a Priority of “Low”. The Action field can be toggled between
Add and Delete.
For 16- and 24-port switches, more port spaces would be displayed to the right of the
Priority listing in each MAC Address line.
The example of Figure 17 shows how two MAC Addresses were defined. Ports 1–5
have been associated with address 07892a310000 with a Low Priority. Ports 1 and 2
have been assigned to address 01a0c2000000 and are assigned a Medium Priority.
Figure 17 — Configure Multicast Filtering Table
NOTE: For an address to be accepted as a valid multicast address, its second digit must be odd. If
the second digit is even, an error is reported in the Help Area.