Configuring Rpt-To-Spt Switchover; Configuring Pim-Ssm; Pim-Ssm Configuration Task List - 3Com MSR 50 Series Configuration Manual

Configuring RPT-to-SPT
Switchover

Configuring PIM-SSM

PIM-SSM Configuration
Task List
should carry out these configurations on the routers that may win the DR election
and on the C-RPs that may win RP elections.
Because the RPT is not necessarily the tree that has the shortest path, the multicast
forwarding path needs to be switched from the RPT to the SPT when the multicast
traffic increases. Initially, a PIM-SM router forwards multicast packets through an
RPT. However, when the traffic rate of multicast packets reaches a threshold, the
receiver-side DR immediately initiates an RPT-to-SPT switchover process.
Both the receiver-side DR and the RP can periodically check the passing-by
multicast packets and thus trigger RPT-to-SPT switchover.
Follow these steps to configure RPT-to-SPT switchover:
To do...
Enter system view
Enter public instance PIM view
or VPN instance PIM view
Configure RPT-to-SPT
switchover
Configure the interval of
checking the traffic rate
threshold before RPT-to-SPT
switchover
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 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.
n
The PIM-SSM model needs the support of IGMPv3. Therefore, be sure to enable
IGMPv3 on PIM routers with multicast receivers.
Complete these tasks to configure PIM-SSM:
Task
"Enabling PIM-SM" on page 1186
"Configuring the SSM Group Range" on page 1186
"Configuring PIM Common Information" on page 1187
Use the command...
system-view
pim [ vpn-instance
vpn-instance-name ]
spt-switch-threshold
{ traffic-rate | infinity }
[ group-policy acl-number
[ order order-value] ]
timer spt-switch interval
Configuring PIM-SSM 1185
Remarks
-
-
Optional
By default, the device
switches to the SPT
immediately after it receives
the first multicast packet from
the RPT.
Optional
15 seconds by default
Remarks
Required
Optional
Optional