I've been dealing with some network issues for the past two weeks and I've run out of ideas as to what to troubleshoot. Here's what I'm seeing:



(The packet loss at 12:14am was a disconnected cable, I was swapping a new one in to test)

Basically, intermittent, and seemingly cyclical 100% packet loss at the first hop, but clean after that. If the machine is idling with no network traffic it tends to disappear, but as soon as something gets launched, the cyclical loss appears and eventually causes disconnects in softwares that rely on stable connections - VoIP, games, etc.

I've spoken with my ISP and they can't see anything from their side, the line seems strong and clear. I've tested two separate modems with them on the phone, both looked great from their side but had identical issues from my side. I've also tried two routers, one brand new, with no difference. I've moved cables around, tried alternate NICs, multiple computers, tried wireless connections vs. ethernet. The packet loss always shows up in one form or another.

The only thing that eliminates this completely and consistently is connecting a PC directly, via Ethernet, into the modem. Any alternate configuration produces this artifact.

I say artifact because I can't seem to see it with other tools. Using cmd, ping is always clean, no packet loss, yet I still see dicsonnects in software and PingPlotter seems to differentiate very specifically between when the line is clean and when something is amiss. I even seem to get good ping - and identical ping between "good" and "bad" signal. You can see that in the above image. What's especially odd is that in the first image you can see that there's packet loss in the first hop but if I run just that IP directly I get this without fail:



I've gotten to the point where I'm unplugging different appliances and playing with my fuse box to see if there's some dirty power or a bad ground introducing some noise but I can't seem to nail anything down and yeah, running out of ideas.

Is there something I'm just woefully overlooking? Does anyone recognize this specific pattern?

Edit: This is what it looks like when I direct connect without the router: