
Operation Manual – Multicast Protocol
H3C S3610&S5510 Series Ethernet Switches
Chapter 6 PIM Configuration
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maintains the current forwarding state for a period of time defined by LAN-delay. If the
downstream router needs to continue receiving multicast data, it must send a prune
override message within the prune override interval; otherwise, the upstream route will
perform the prune action when the LAN-delay timer times out.
A hello message sent from a PIM router contains a generation ID option. The
generation ID is a random value for the interface on which the hello message is sent.
Normally, the generation ID of a PIM router does not change unless the status of the
router changes (for example, when PIM is just enabled on the interface or the device is
restarted). When the router starts or restarts sending hello messages, it generates a
new generation ID. If a PIM router finds that the generation ID in a hello message from
the upstream router has changed, it assumes that the status of the upstream neighbor
is lost or the upstream neighbor has changed. In this case, it triggers a join message for
state update.
If you disable join suppression (namely, enable neighbor tracking), the upstream router
will explicitly track which downstream routers are joined to it. The join suppression
feature should be enabled or disabled on all PIM routers on the same subnet.
I. Configuring hello options globally
Follow these steps to configure hello options globally:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter PIM view
pim
—
Configure the priority for
DR election
hello-option dr-priority
priority
Optional
1 by default
Configure PIM neighbor
timeout time
hello-option holdtime
interval
Optional
105 seconds by default
Configure the prune delay
time (LAN-delay)
hello-option lan-delay
interval
Optional
500 milliseconds by
default
Configure the prune
override interval
hello-option
override-interval
interval
Optional
2,500 milliseconds by
default
Disable join suppression
hello-option
neighbor-tracking
Optional
Enabled by default
II. Configuring hello options on an interface
Follow these steps to configure hello options on an interface: