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Step
Command
Remarks
enter VPN instance view.
vpn-instance-name
3.
Configure an RD for the VPN
instance.
route-distinguisher
route-distinguisher
Not configured by default.
4.
Enable IP multicast routing.
multicast routing-enable
Disabled by default.
5.
Enter interface view.
interface
interface-type
interface-number
N/A
6.
Bind the interface with a VPN
instance.
ip binding vpn-instance
vpn-instance-name
By default, an interface belongs to
the public network, and is not
bound with any VPN instance.
7.
Enable PIM-DM.
pim dm
Disabled by default.
For more information about the
ip vpn-instance
,
route-distinguisher
, and
ip binding
vpn-instance
commands, see
MPLS Command Reference.
Enabling state-refresh capability
Pruned interfaces resume multicast forwarding when the pruned state times out. To prevent this, the
router with the multicast source attached periodically sends an (S, G) state-refresh message. The
state refresh message is forwarded along the initial multicast flooding path of the 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 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 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 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 accepts a new state-refresh message, refreshes its own PIM-DM state,
and resets 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. The state refresh message stops being forwarded when the TTL
value comes down to 0. A state refresh message with a large TTL value might cycle on a small
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:
