At the behest of Comcast, I upgraded a fairly new DOCSIS 3.0 modem to the Motorola MB8600 (3.1). Download speed is 175Mbps+, but upload speed is around 1-2Mbps (see test snapshot below). I have tried power cycling the modem and a hard reset (holding the recessed reset button down for 30 secs).
I can ping the modem's administrative IP (192.168.100.1), but can't reach the web page - nmap shows tcp/80 and tcp/443 as "open/filtered". I've also tried putting the router on the same subnet (192.168.100.2), but that doesn't seem to work either.
Any ideas? Maybe the CMTS gear needs tweaking?