H3C Technologies H3C S12500 Series Switches - Manual (Page 143)

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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, of which some 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.
To configure state-refresh parameters:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter public network PIM view or
VPN instance PIM view. pim [ vpn-instance
vpn-instance-name ]
N/A
3. Configure the interval between
state-refresh messages.
state-refresh-interval interval
Optional.
60 seconds by default.
4. Configure the time to wait before
receiving a new state-refresh
message.
state-refresh-rate-limit interval
Optional.
30 seconds by default.
5. 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 (graft retry period) until it receives a graft-ack message from the upstream router.
For more information about the configuration of other timers in PIM-DM, see "
Configuring PIM common
timers ."
To configure graft retry period:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter interface view.
interface interface-type
interface-number
N/A