Some eth0 connection status cause unicast & multicast can't play

Hi Expert,

I’d like to ask about an issue related to unicast and multicast playback. The problem appears to be associated with the status of whether eth0 has obtained an IP address. The detailed description is as follows:

Issue 1:
When the system boots up and has not yet obtained an IP address, the RTSP server and media are already ready. At this point, if a local client tries to initiate a multicast connection, the DESCRIBE and SDP exchange succeed, but the PLAY request returns a 503 error. Even after the IP address becomes available, there is still no UDP multicast traffic observed.
Question: Does a multicast connection require the IP interface (e.g., eth0) to be ready beforehand?

Issue 2:
Following the same scenario above, unicast connections also fail during this period.
Question: Can a multicast connection failure affect the ability to establish unicast connections as well?

environment:
OS: Linux NightScan 4.19.91 #1 SMP PREEMPT Thu Jun 26 15:04:16 CST 2025 armv7l Toybox
gstreamer version: 1.22.12

Thank you!

Yes. An IP address is required for any unicast or multicast traffic to succeed on that network interface.