3Com SuperStack II 3300 User Manual page 79

Administering IP
Multicast Interfaces
Displaying Multicast
Interface Information
Enabling Multicast
Interfaces
The IP multicast interface options allow you to enable and disable
multicast characteristics on previously defined IP interfaces.
Multicast Interface Characteristics
A multicast interface has the following characteristics:
DVMRP Metric Value — Determines the cost of a multicast
interface.The higher the cost, the less likely it is that the packets will
be routed over the interface. The default value is 1.
Time To Live (TTL) Threshold — Determines whether the interface
forwards multicast packets to other switches and routers in the
subnetwork. If the interface TTL is greater than the packet TTL, then
the interface does not forward the packet. The default value is 1,
which means that the interface forwards all packets .
To display information about all the multicast interfaces, enter the
following at the top-level menu:
ip multicast interface display
The following example shows a multicast interface display:
Multicast routing is enabled on all existing IP interfaces unless you have
specifically disabled it. Use the command described in this section to
change the characteristics of an existing interface or to enable an
interface that you had previously disabled.
To enable or change a multicast interface:
1 Enter the following at the top-level menu:
ip multicast interface enable
The following prompt is displayed:
Enter an IP interface index (1-3):
Administering IP Multicast Routing 79