3Com Switch 8800 Advanced Software V5 Configuration Guide

Configuring PIM-SM 577
will accept a new state refresh message, refresh its own PIM state, and reset the
waiting timer.
The TTL value of a state refresh message decrements by 1 whenever it passes a
device before it is forwarded to the downstream node until the TTL value comes
down to 0. In a small network, a state refresh message may cycle in the network.
To effectively control the propagation scope of state refresh messages, you need
to configure an appropriate TTL value based on the network size.
Follow these steps to configure state refresh parameters:
Configuring PIM-DM
Graft Retry Period
In PIM-DM, graft is the only type of message that uses the acknowledgment
mechanism. In a PIM-DM domain, if a device does not receive a graft-ack message
from the upstream device within the specified time after it sends a graft message,
the device keeps sending new graft messages at a configurable interval, namely
graft retry period, until it receives a graft-ack from the upstream router.
Follow these steps to configure graft retry period:
n
For the configuration of other timers in PIM-DM, refer to “Configuring PIM
Common Timers” on page 590.
Configuring PIM-SM
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A device can serve as a C-RP and a C-BSR at the same time.
PIM-SM Configuration
Task L is t
Complete these tasks to configure PIM-SM:
To do... Use the command... Remarks
Enter system view system-view -
Enter PIM view pim -
Configure the interval
between state refresh
messages
state-refresh-interval
interval
Optional
60 seconds by default
Configure the time to wait
before receiving a new state
refresh message
state-refresh-rate-limit
interval
Optional
30 seconds by default
Configure the TTL value of
state refresh messages
state-refresh-ttl ttl-value Optional
255 by default
To do... Use the command... Remarks
Enter system view system-view -
Enter VLAN/POS interface
view
interface interface-type
interface-number
-
Configure graft retry period pim timer graft-retry
interval
Optional
3 seconds by default