3Com S7906E - Switch, Configuration Manual

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All the interfaces of the same device must work in the same IPv6 PIM mode.
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IPv6 PIM-DM cannot be used for IPv6 multicast groups in the IPv6 SSM group range.
For details about the multicast ipv6 routing-table command, see IPv6 Multicast Routing and
Forwarding Commands in the IP Multicast Volume .
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 the interval for sending such messages.
A router may receive multiple state-refresh messages within a short time, of which some may be
duplicated messages. To keep a router from receiving such duplicated messages, you can configure
the time the router must wait before receiving the next state-refresh message. If a 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.