@keyser pfsense is upstream and has no switch ports..
pfsense -- sg300-28 --- sg300-10 -- nvr
The sg300-10 port connected to the poe port on the back of the nvr to put a leg into that L2 was the one going up down.. The actual nvr lan port was fine. But there was no possible way for there to be any sort of loop that is for sure. The sg300-10 was the one logging the up/down.
Yeah the poe didn't dawn on me for a bit.. And I tried turning off auto neg, turning off green ethernet, etc. etc.. tried all kinds of settings.
Is it poe related - no I am not 100% sure on that.. But I know if your going to connect another switch to poe port of an upstream switch, if possible should make sure poe is disabled on that port, etc. But with the nvr there is no way to do anything like that..
What I can say is no longer seeing any packet loss at all - which before there was some, that would go together with a up/down of the port even if very short 2 seconds, etc.. And there are no log entries for up down on that port connected to the nvr poe port with the little mini between the sg300-10 and the NVR poe port.. And the mini is being powered by the poe coming off the nvr port.
edit: so before I was seeing some minor packet loss
Packets: Sent = 386, Received = 383, Lost = 3 (0% loss)
Now after I put the mini between I don't see any
Packets: Sent = 1524, Received = 1524, Lost = 0 (0% loss)