3Com 3C10402B Administrator's Manual page 44

44 C 2: S
HAPTER YSTEM
S
ETTINGS
The system IGMP is an implementation of administratively scoped
IP multicast that uses three scopes of administration:
Local scope — Limited by local routers with IP addresses 239.255.0.0
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through 239.255.0.16
Organizational local scope — Limited by boundary routers with
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IP addresses 239.192.0.0 through 239.192.0.14
Global scope — IP addresses 224.2.0.0 through 224.2.127.253
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IGMP might not be available in all systems or network topologies. All
routers between the various components must support IGMP and the
necessary router protocols to establish a path for the IP multicast packets.
Each event that occurs in an IGMP setup, such as taking a telephone off
the hook, causes a packet of 200 Kb to 300 Kb to be sent.
The default settings for the IP multicast addresses function in most
network environments. Certain addresses are reserved.
The MAC address and the IP address displayed on any one line of the
Multicast Address List window are not related.
There are two methods for selecting multicast addresses:
Change IP — Lets you select a starting address for all entries.
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Changing IP multicast addresses is a quick way to change the range of
system multicast addresses to avoid conflicts with other equipment on
your network.
Change bins — Lets you change a single entry by selecting from a list
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of available bins. Changing IP bins is useful for changing a single
address that might conflict with another system device. Consult your
network administrator to determine which address is in conflict and
the new address to choose.
To change multicast addresses:
1 Log on to the NBX NetSet utility using the administrator login ID and
password.
2 Click System-Wide Settings > Multicast Addresses.
3 See the online Help for more information.