H3C Technologies H3C S7500E Series Switches - Manual (Page 368)

13-17
new state-refresh message is received within the waiting time, the router will discard it; if this
timer times out, the router will accept a new state-refresh message, refresh its own IPv6
PIM-DM state, and reset the waiting timer.
The hop limit value of a state-refresh message decrements by 1 whenever it passes a router
before it is forwarded to the downstream node until the hop limit 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 hop limit
value based on the network size.
It is recommended to perform the following configurations on all routers in the IPv6 PIM
domain.
Follow these steps to configure state-refresh parameters:
To do... Use the command... Remarks
Enter system view system-view —
Enter IPv6 PIM view pim ipv6 —
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 hop limit value of
state-refresh messages
state-refresh-hoplimit
hoplimit-value
Optional
255 by default
Configuring IPv6 PIM-DM Graft Retry Period
In IPv6 PIM-DM, graft is the only type of message that uses the acknowledgment mechanism.
In an IPv6 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
from the upstream router.
Follow these steps to configure IPv6 PIM-DM graft retry period:
To do... Use the command... Remarks
Enter system view system-view —
Enter interface view
interface interface-type
interface-number
—
Configure graft retry period
pim ipv6 timer graft-retry
interval
Optional
3 seconds by default