Slow internet speeds both wired and wireless on C7000v2

[Magnamus]

I just received a Nighthawk C7000v2 to replace the piece of junk modem/router Comcast provided me years ago when I first signed up for their service. The speeds on their modem were OK, but the router part itself was unstable and wireless was useless, so I ended up using their modem in gateway mode and used an old wireless router for routing and Wifi duty. Anyway, I did the setup of the Netgear device and it worked right away without much issues, except for the speed. I then talked to Comcast to register the device under my account, but that still made no difference in speed.

My plan gets up to 200mbps, and with their modem I got between 70 to 120mpbs. With the Netgear modem/router I get up to 20mbps wired, and really slow wifi on both 2.4ghz and 5ghz. The connection from my devices to the router look normal in the wireless properties, but the actual internet speed is so slow I'm having trouble connecting to most websites. I even tried downloading files, but on 2.4ghz I only get DSL speeds between 80 and 120kbps.

I tried resetting it to factory settings several times, and even the 30/30/30 second reset. The speed doesn't change. I disabled WMM under Advanced Setup/Wireless, but it made very little difference. This device gets the firmware through the ISP, and it looks like it's up to date, so I don't know what else to do.

I contacted Comcast today, but they insist nothing is wrong on their end. I asked them to check if they had the right settings for this modem, and I even asked them if they had sent the wrong boot file after reading about it on this forum, but they just said there was nothing wrong with that right away, so I don't know if they actually checked. They're sending a technician tomorrow, so I'd like to know if somebody went through this experience and if there's something I should mention to their tech.

[Magnamus · Accepted solution]

Just a quick update, the Comcast tech came by today and found problems with high noise levels and really high downstream numbers on the cable leading to the box outside my building. There was also a filter placed on my wire in the same box that apparently was placed by mistake by somebody working on another apartment.

The problem is fixed and there was nothing wrong with the modem router, so please marked this as solved.

[Magnamus · Accepted solution]

Just a quick update, the Comcast tech came by today and found problems with high noise levels and really high downstream numbers on the cable leading to the box outside my building. There was also a filter placed on my wire in the same box that apparently was placed by mistake by somebody working on another apartment.

The problem is fixed and there was nothing wrong with the modem router, so please marked this as solved.