Setting the TTL Value of State-Refresh Messages
Context
When a device receives a State-Refresh message, it reduces the time to live (TTL) value of the message by 1 and forwards the message to downstream devices. The State-Refresh message is transmitted on the network until its TTL value reduces to 0. On a small-scale network, State-Refresh messages with a large TTL value are transmitted circularly. To control the transmission range of State-Refresh messages, set a proper TTL value for State-Refresh messages according to the network scale.
Because State-Refresh messages are originated from the first-hop device connected to a multicast source, the TTL value of State-Refresh messages must be configured on the first-hop device.