Install guide

IP Multicasting 7
protocols. The broadcast-and-prune mechanism in PIM Dense Mode uses a
technique called reverse path forwarding (RPF), in which a multicast datagram is
forwarded only when the receiving interface is the one used to forward unicast
datagrams to the source of the datagram.
Configuring PIM Dense Mode
PIM multicasting routing is disabled by default and must be enabled on the
switch before any PIM configuration takes effect. However, we recommend
that the PIM configuration be completely set up on the switch before PIM is
enabled. To enable or disable PIM, use the commands:
enable pim
disable pim
For PIM Dense Mode multicast routing to operate on the switch, each interface
over which it is to send and receive multicast routing messages and multicast
packets must be assigned to PIM-DM.
By default PIM interfaces are set to use Sparse Mode when they are added. To
add a PIM-DM interface, use the command:
add pim interface=interface mode=dense [other-options...]
To delete an interface, use the command:
delete pim interface=interface
The IP configuration of an interface cannot be changed while PIM is attached to
the interface. The PIM interface must first be deleted, and then re-added after
the IP changes have been made.
To modify a PIM interface, use the command:
set pim interface=interface [mode={dense|sparse}]
[other-options...]
State Refresh messages can be used in a PIM-DM domain to reduce
unnecessary multicast traffic. Instead of a source repeatedly flooding
downstream routers with multicast packets and repeatedly receiving prune
messages, a State Refresh message maintains an existing prune. By default the
switch cannot initiate or process State Refresh messages. To enable this
functionality on an interface, use one of the commands:
add pim interface=interface mode=dense srcapable=yes
[other-options...]
set pim interface=interface srcapable=yes [other-options...]
To restart all PIM processes on an interface, resetting the PIM timers, route
information and counters for the interface, use the command:
reset pim interface=interface
To display information about PIM interfaces, use the command:
show pim interface