Isn't too long for MRIB_DEFAULT_LIFETIME=125s?

[zhao-wuji-ahh]

1. The validity period of each multicast source route is 125 seconds.

2. If the multicast stream arrives first, and then a client connects, it will take up to 125 seconds before it can play normally.

We can reduce the timeout to handle this.But setting it too short is also unreasonable. So Is there a better way to achieve immediate playback?

[zhao-wuji-ahh]

@sbyx