3Com Switch 8800 Advanced Software V5 Configuration Guide

Configuring PIM-SM 585
multicast group), or when the RP formally starts receiving multicast data from the
multicast source, the RP sends a register-stop message to the source-side DR.
Upon receiving this message, the DR stops sending register messages
encapsulated with multicast data and enters the register suppression state.
In a probe suppression cycle, the DR can send a null register message (a register
message without multicast data encapsulated), a certain length of time defined by
the probe time before the register suppression timer expires, to the RP to indicate
that the multicast source is active. When the register suppression expires, the DR
starts sending register messages again. A smaller register suppression timeout
setting will cause the RP to receive bursting multicast data more frequently, while a
larger timeout setting will result in a larger delay for new receivers to join the
multicast group they are interested in.
Follow these steps to configure PIM-SM register-related parameters:
n
Typically, you need to configure the above-mentioned parameters on the
receiver-side DR and the RP only. Since both the DR and RP are elected, however,
you should carry out these configurations on the devices that may win the DR
election and on the C-RPs that may win RP elections.
Disabling RPT-to-SPT
Switchover
When a Switch 8800 serves as the receiver-side DR, by default, it initiates an
RPT-to-SPT switchover process immediately after receiving the first multicast
packet along the RPT. You can disable the RPT-to-SPT switchover function with the
following command.
Follow these steps to disable RPT-to-SPT switchover:
To do... Use the command... Remarks
Enter system view system-view -
Enter PIM view pim -
Configure a filtering rule for
register messages
register-policy acl-number Optional
No register filtering rule by
default
Configure the device to
calculate the checksum based
on the entire register
messages
register-header-checksum Optional
By default, the checksum is
calculated based on the
header of register messages
Configure the register
suppression timeout time
register-suppression-timeo
ut interval
Optional
60 seconds by default
Configure the probe time probe-interval interval Optional
5 seconds by default
To do... Use the command... Remarks
Enter system view system-view -
Enter PIM view pim -