So yesterday I discovered a odd problem, every 30 seconds I was getting packet loss. At first I thought it was just the internet, but was my entire LAN.
In addition it coincided with a spike of traffic I seen on my main desktop, it was only a spike to around 700kB/sec but a spike noticeable over idle traffic.
I spent ages trying to get to the bottom of it, a few key things.
When I disconnected my second openwrt switch from my LAN, the packet loss stopped, although spikes were still going to my PC.
I also discovered disconnecting my firewall from the main switch, also stopped the packet loss but in addition also stopped the spikes.
I looked at my firewall (pfsense) and the culprit was upnp, something known to be a security risk, but it was enabled in the past as it was the only way I could get UNO to work online multiplayer. As soon as I disabled upnp, the spikes stopped, and everything is fine again with all equipment connected.
So the conundrum I have been left with is how such a small spike of internet traffic can kill a gigabit LAN, can internet traffic cause a broadcast storm somehow? I didnt inspect the traffic after I discovered it was upnp, so I have no information on what the payload was. I briefly enabled it again today and the spikes have stopped, but have disabled it again given what happened.
Welcome any thoughts.