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IPv6 PIM-DM domain, to refresh the prune timer state of all routers on the path. A multi-access
subnet can have the state-refresh capability only if the state-refresh capability is enabled on all IPv6
PIM routers on the subnet.
To enable the state-refresh capability:
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter interface view.
interface
interface-type
interface-number
N/A
3.
Enable the state-refresh
capability.
pim ipv6 state-refresh-capable
Optional.
Enabled by default.
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. Some messages might
be duplicated messages. To keep a router from receiving such duplicated messages, you can
configure the time that the router must wait before receiving the next state-refresh message. If the
router receives a new state-refresh message within the waiting time, it discards 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. The state refresh message stops being forwarded when the
hop limit comes down to 0. A state refresh message with a large hop limit value might cycle on a
small network. To control the propagation scope of state-refresh messages, you must configure an
appropriate hop limit value based on the network size.
Perform the following configurations on all routers in the IPv6 PIM domain.
To configure state-refresh parameters:
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter IPv6 PIM view.
pim ipv6
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 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
