Is the Netgear CM700 modem compatible with the Netgear Model R6700v3 router?

[shaddock]

Is the Netgear CM700 modem compatible with the Netgear Model R6700v3 router? It started to slow down a month ago and this is what the cable company is claiming is the issue. Non-compatibility

[shaddock]

I am paying for 400 mbps and barely hitting 10% during a speed test.

[plemans]

They are compabile. So we need to figure out where the slowdown is coming from.

So start here.

directly connect a pc to the CM700. Speedtest it on dslreports.org. What speeds do you get?

Also, take a screen snip of your cm700 modem connections page. many isps like to blame 3rd party devices when its actually their signal. 

If everything is checking out on the modem, then we'll move onto the router.