3Com Switch 8800 Configuration Guide Chapter 28 PIM-DM Configuration
28-3

IV. Graft

When the pruned downstream node needs to be restored to the forwarding state, the
node will send a graft packet to inform the upstream node.
28.2 PIM-DM Configuration
1) PIM-DM basic configuration includes:
z Enabling multicast
z Enabling PIM-DM
2) PIM-DM advanced configuration includes:
z Configuring the time interval for ports to send Hello packets
z Entering the PIM view
z Configuring filtering of multicast source/group
z Configuring filtering of PIM neighbor
z Configuring the maximum number of PIM neighbor on an interface
z Clearing PIM neighbors

28.2.1 Enabling Multicast

Refer to Chapter 26 Common Multicast Configuration.

28.2.2 Enabling PIM-DM

PIM-DM needs to be enabled in configuration of all interfaces.
After PIM-DM is enabled on an interface, it will send PIM Hello messages periodically
and process protocol packets sent by PIM neighbors.
Perform the following configuration in VLAN interface view.
Table 28-1 Enabling PIM-DM
Operation Command
Enable PIM-DM on an interface pim dm
Disable PIM-DM on an interface undo pim dm
It’s recommended to configure PIM-DM on all interfaces in non-special cases. This
configuration is effective only after the multicast routing is enabled in system view.
Once enabled PIM-DM on an interface, PIM-SM cannot be enabled on the same
interface and vice versa.