346
NOTE:
For more information about the
multicast ipv6 routing-enable
command, see the
IP Multicast
Command Reference.
Enabling state-refresh capability
Pruned interfaces resume multicast forwarding when the pruned state times out. To prevent this, the
router directly connected with the IPv6 multicast source periodically sends an (S, G) state-refresh
message, which is forwarded hop by hop along the initial flooding path of the IPv6 PIM-DM domain, to
refresh the prune timer state of all the 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.
Follow these steps to enable the state-refresh capability:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter interface view
interface
interface-type interface-
number
—
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 an 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 receiving the next state-refresh message. If the router receives a new
state-refresh message 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 might cycle in the 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.
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
Summary of Contents for A5500 EI Switch Series
Page 12: ...xii Conventions 425 Index 427 ...