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Configuring state-refresh parameters – H3C Technologies H3C S7500E Series Switches User Manual

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can have the state-refresh capability only if the state-refresh capability is enabled on all 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 state-refresh

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 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 PIM-DM

state, and reset 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 until the TTL 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 TTL value based on the

network size.

It is recommended to perform the following configurations on all routers in the PIM domain.

Follow these steps to configure state-refresh parameters:

To do...

Use the command...

Remarks

Enter system view

system-view

Enter public instance PIM view or VPN

instance PIM view

pim [ vpn-instance

vpn-instance-name ]

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 TTL value of

state-refresh messages

state-refresh-ttl ttl-value

Optional

255 by default