H3C Technologies H3C S10500 Series Switches - Manual (Page 160)

145
Configuring state-refresh parameters
The router directly connected with the multicast source periodically sends state-refresh messages. You can
configure the interval for sending such messages.
A router might receive multiple state-refresh messages within a short time, and some of them might be
duplicated messages. To keep a router from receiving such duplicated messages, you can configure the
time that the router must wait before it receives next state-refresh message. If the router receives a new
state-refresh message within the waiting time, it discards the message. If this timer times out, the router
will accept a new state-refresh message, refresh its own PIM-DM state, and reset the waiting timer.
The TTL value of a state-refresh message decrements by 1 whenever it passes a router before it is
forwarded to the downstream node until the TTL value comes down to 0. In a small network, a
state-refresh message might cycle in the network. To effectively control the propagation scope of
state-refresh messages, configure an appropriate TTL value based on the network size.
Perform the following configurations on all routers in the PIM domain.
Follow these steps to configure state-refresh parameters:
To do... Use the command... Remarks
Enter system view system-view —
Enter public network PIM view or VPN
instance PIM view pim [ vpn-instance
vpn-instance-name ]
—
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
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 router does not receive a graft-ack message from the upstream router within the specified
time after it sends a graft message, the router keeps sending new graft messages at a configurable
interval—namely graft retry period, until it receives a graft-ack message from the upstream router.
Follow these steps to configure the graft retry period:
To do... Use the command... Remarks
Enter system view system-view —
Enter interface view
interface interface-type
interface-number
—
Configure the graft retry period pim timer graft-retry interval
Optional
3 seconds by default.