I observe an interesting (to me ) issue.

I have a PC directly connected to my TL-SG108E. I have a mini-PC that's connected to another switch. The switches are connected to each other.

Generally, everything works very well.

However, I noticed an issue when I stream audio via unicast RTP from the PC to the mini-PC.

Initially, RTP packets (unicast UDP) for the stream get forwarded only to the port that's connected to the other switch and, so, in the correct direction towards the mini-PC.

But after a few minutes the switch starts sending those packets to all ports (except the one they came from).

I can tell that by the blinking lights on all active ports and also by running wireshark / tcpdump on a laptop that's connected to the TL-SG108E as well.

If I ping the mini-PC then the packets start flowing normally again.

But after a short while they begin to be broadcasted again.

My guess is that during such streaming the packets (RTP/UDP) are going in one direction.

The switch sees packets going to a certain MAC address but no packets from that address.

So, maybe after a while it starts "suspecting" that those packets could be getting lost, etc. In other words it starts "suspecting" that it is sending the packets to a wrong port.

So, it starts broadcasting those packets to all ports.

If I ping the mini-PC then it replies and the switch sees the correct port and starts using it.

But that does not last for long.

I wonder if all MAC addresses have such a short age in the switch MAC table.

Or if it is the traffic pattern that makes the age so short.

And if anything could be done to fix / improve the situation.