3Com Switch 4800G 24-Port Configuration Manual page 651

n
Disabling RPT-to-SPT
Switchover
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To do...
Configure a filtering rule for
register messages
Configure the device to
calculate the checksum based
on the entire register
messages
Configure the register
suppression timeout time
Configure the probe time
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 routers that may win the DR
election and on the C-RPs that may win RP elections.
Initially, multicast traffic flows along an RPT to the receivers. By default, the
last-hop switch initiates an RPT-to-SPT switchover process when it receives the first
multicast packet from the RPT. You can disable RPT-to-SPT switchover through the
following configuration.
Follow these steps to disable RPT-to-SPT switchover:
To do...
Enter system view
Enter PIM view
Disable RPT-to-SPT switchover spt-switch-threshold
The support for the timer spt-switch command depends on the specific
■
device model.
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 routers that may
win the DR election and on the C-RPs that may win RP elections.
If the multicast source is learned through MSDP, the device will switch to the
■
SPT immediately after it receives the first multicast packet from the RPT, no
matter how big the traffic rate threshold is set (this threshold is not
configurable on a switch).
Use the command...
register-policy acl-number
register-header-checksum
register-suppression-timeo
ut interval
probe-interval interval
Use the command...
system-view
pim
infinity [ group-policy
acl-number [ order
order-value] ]
Configuring PIM-SM 651
Remarks
Optional
No register filtering rule by
default
Optional
By default, the checksum is
calculated based on the
header of register messages
Optional
60 seconds by default
Optional
5 seconds by default
Remarks
-
-
Optional
By default, the device
switches to the SPT
immediately after it receives
the first multicast packet from
the RPT.