NETGEAR Cable Modem CM400 Compatible with Cable Providers Xfinity by Comcast, Spectrum, Cox | for Cable Plans Up to 100 Mbps | DOCSIS3.0, Black (CM400-100NAS)

Greate ,Cheap , easy to set up , and works perfect ! Perfect modem if you use Internet on your ps4 or phone and want a stonger connection for multiple devices . Has 3 total wires in the box it comes in. I baught this not realizing it didnt come with built in wifi connection, i still needed to hook up to a wifi modem, it still was perfect since I had a wifi mode already. It was good deal i couldn't pass up ! It connected cox internet service perfectly - Has normal modem issues that you normally expect once in a blue moon , always a common thing when dealing with technology , you can restart the box and the connection will be fixed. 2 months now and still going strong . Update: still runs perfectly one year later !! Hope this helped anyone !

The CM400 is primarily a simple device to install. Due to the restrictions placed on us by the cable provider, i.e. firmware updates, a particular downstream channel frequency and the like, there is however only one controlling feature for us to modify. Compared to the many other units I've used this cable modem does allow us to at least find a starting frequency then locking into a channel best suited to my custom router/networking needs. It does take a few extra tries to find that one frequency I'm looking for, that's the one controlling feature I like that Netgear gives us. My regional cable provider is not always in alignment to my speed freakish needs limited to 110Mbps. :<(' The CM400 is a very reliable and sound unit. Bought April 2017, over a year of quality service.

I bought this modem 3 weeks ago, and since then I haven't had no issues whatsoever, I got the same speed as the modem that Time Warner Cable had gave me , no complaints yet. I got 103 Mbps on the download, and almost 10 Mbps upload which I don't care about to much. Works great, set it up its pretty easy , just call your cable company to register the ESN and that's it . If after that you don't have Internet service call Netgear they will help set it up as well.

I bought this prior to ordering Xfinity internet service. My apartment building had Comcast setup for other units, so when this arrives, I plugged it into the cable jack, called Comcast, and activated my internet. Total process took about 15 minutes from opening the box. Now I'm not paying Comcast $10/month for a lease on a similar unit. This unit doesn't have wireless internet, or any ability to support phone/cable TV, but it doesn't say it does and I don't need it. I connect this to a wireless router I have use that for WIFI. This works very well for connection to Comcast Xfinity internet service.

ORIGINAL REVIEW: Bought this modem to replace another NETGEAR modem that lasted one month beyond it's warranty date... This one only lasted one month, so I'm replacing it with another of the same. I'll give it one more try -- will update this review if the new one lasts longer. UPDATED REVIEW: Ok, the new one started experiencing the same issues after just a few weeks. I decided to do more in-depth research about this and here's what I found... This modem uses a onboard chip, known as "Puma 6". This chipset has a known issue for causing "buffer bloat", which can result in high latency. If you run the proper test, you will likely see it show up as network jitter while your modem is under load. The problem can come and go, making it difficult to detect, but there are good tests you can run to see it. Do a little research and you'll find this information summarized on other sites as well. This issue will not affect everyone. It depends on how demanding your internet use is, and what applications you are using. For instance, you wouldn't likely notice if you are just browsing online and reading emails. If you are gaming, it is very likely you will notice. Also, there are some reports of this issue being regional due to the firmware that is rolled out in different areas, but I couldn't find any firm data on that so that seems speculative at this point. Additionally, there was a security bulletin put out by NETGEAR (in 2017) stating this is one of several modems susceptible to DoS attacks. To be fair, most people wouldn't be a victim of such an attack, but it's another thing to keep in mind. I couldn't find any information stating whether they have fixed this issue or not yet. In summary, if you use the internet like my grandma, don't mind daily modem resets, and internet speeds 20% of what the modem advertises (or somehow end up like one of the lucky few without issues using this modem), then this will likely work out just fine for you. If that doesn't describe you, then research what modems come with the Puma 6 chipset and DO NOT BUY THOSE.

This modem was good at first but Comcast told us that they no longer support this product. Before that happened though, the modem was easy to install. My apartment building wiring was messed up so I had to get Comcast on the phone to help and after running their tests they said the equipment was good (don't really know how important that is now since they said they no longer support it). Our wifi signal was kind of weak but we were still able to use it.

I recently signed up for a new account with xfinity internet and I knew it would be a better option for me to save some money and order a cable modem instead of leasing one of theirs. After hours of searching I found my self purchasing this product because of it's affordable price and the fact that it has a wireless router built in. Since the modem I purchased was refurbished I was a bit skeptical that I would have complications setting it up because the serial number was scratched out with a permanent marker. But thankfully I can an easy set up with xfinity because they only needed the MAC number for set up. The instillation was quick and easy, I could have not been any happier with this product! I have had this for 2 weeks and the internet has never been faster. I haven't experienced any issues thus far.

The device is missing the EURO-DOCSIS connection. Can be used only in USA. The customer support was kind and responsive. They refunded me in no time!

Nice