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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)

4.1 4.1 out of 5 stars 1,657 ratings

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Available at a lower price from other sellers that may not offer free Prime shipping.
DOCSIS 3.0

Purchase options and add-ons

Brand NETGEAR
Internet service provider spectrum, optimum, cox, xfinity
Connectivity Technology Wireless
Total Ethernet Ports 1
Color Black

About this item

  • ELIMINATE MONTHLY CABLE MODEM RENTAL FEES - Up to $156 per year
  • DOCSIS 3. 0 Cable Modem with 1 Gigabit Ethernet port. One (1) Gigabit Ethernet port with auto-sensing technology
  • Up to 340Mbps download and upload speed. Separate router required for WiFi. 8x4 channel bonding.
  • DOCSIS 3. 0 unleashes 8x faster download speeds than DOCSIS 2. 0
  • Ideal for streaming HD videos, faster downloads, and high-speed online gaming
  • Required for the fastest cable Internet speed tiers
  • Compatible with Xfinity from Comcast, Spectrum, Cox, & more. Not compatible with bundled voice services.
  • Memory storage capacity: 64.0 MB
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$64.99 ($3.53/oz)
Get it as soon as Tuesday, Apr 2
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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)
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)
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ARRIS Surfboard S33 DOCSIS 3.1 Multi-Gigabit Cable Modem | Approved for Comcast Xfinity, Cox, Spectrum & More | 1 & 2.5 Gbps Ports | 2.5 Gbps Max Internet Speeds | 4 OFDM Channels | 2 Year Warranty
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Price$64.99$99.99$39.95-29% $162.86
List:$229.99
-5% $179.99
Typical:$189.99
-10% $197.97
List:$219.99
Delivery
Get it as soon as Tuesday, Apr 2
Get it as soon as Tuesday, Apr 2
Get it as soon as Tuesday, Apr 2
Get it as soon as Tuesday, Apr 2
Get it as soon as Tuesday, Apr 2
Get it as soon as Tuesday, Apr 2
Customer Ratings
Easy to install
4.0
4.4
4.2
4.2
4.4
4.2
WiFi signal
3.5
3.8
3.5
3.8
4.1
3.7
Tech Support
3.1
3.1
2.9
3.4
3.7
3.2
Value for money
2.0
4.3
4.1
3.8
3.8
Sold By
NDR Solutions
Hitron Americas
Techa Distribution
Amazon.com
Rustic Wholesale
Verdi!
connectivity tech
Wireless
Ethernet
Ethernet
Ethernet
Ethernet, Wi-Fi
Ethernet
ethernet ports
1
2
1
1
2
2
number of ports
3
3
1
2
data transfer rate
340 megabits per second
1 gigabits per second
1000 megabits per second
300 megabits per second
2500 megabits per second
max downstream rate
343 megabits per second
1 gigabits per second
960 megabits per second
1029 megabits per second
1 gigabits per second
2500 megabits per second
max upstream rate
123 megabits per second
960 megabits per second
246 megabits per second
2.5 gigabits per second
modem type
cable
data modem
cable
cable
dsl
cable

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    Warranty & Support

    Amazon.com Return Policy:You may return any new computer purchased from Amazon.com that is "dead on arrival," arrives in damaged condition, or is still in unopened boxes, for a full refund within 30 days of purchase. Amazon.com reserves the right to test "dead on arrival" returns and impose a customer fee equal to 15 percent of the product sales price if the customer misrepresents the condition of the product. Any returned computer that is damaged through customer misuse, is missing parts, or is in unsellable condition due to customer tampering will result in the customer being charged a higher restocking fee based on the condition of the product. Amazon.com will not accept returns of any desktop or notebook computer more than 30 days after you receive the shipment. New, used, and refurbished products purchased from Marketplace vendors are subject to the returns policy of the individual vendor.
    Product Warranty: For warranty information about this product, please click here. [PDF ]

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    NETGEAR

    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)


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    Product guides and documents

    Product Description

    The NETGEAR CM400 High Speed Cable Modem provides a connection to high-speed cable Internet, up to 340Mbps. It is Cable Labs certified and with DOCSIS 3. 0 is 8X faster than 2. 0. It is compatible with U. S. cable Internet providers like Cablevision, Cox, Time Warner Cable, XFINITY & more.

    Customer reviews

    4.1 out of 5 stars
    4.1 out of 5
    1,657 global ratings

    Customers say

    Customers like the performance, ease of setup, and value of the networking router. For example, they mention it works well, is easy to connect to a separate wireless router, and is great for the money. That said, some complain about the connectivity and heating issues. Opinions are mixed on speed and quality.

    AI-generated from the text of customer reviews

    251 customers mention177 positive74 negative

    Customers like the performance of the router. They mention that it works well, does the job admirably, and has a full signal. Some say that the initial performance was pretty good, and the router has done the job for six months now.

    "Greate ,Cheap , easy to set up , and works perfect !..." Read more

    "this modem is really my new favorite. works extremely well, no lag, no internet connection problems like my previous arris which was not good...." Read more

    "...The main reason was heating. These modems gets very warm and needs to run 24/7 there should be cooling units to make them last." Read more

    "...Works great, set it up its pretty easy , just call your cable company to register the ESN and that's it ...." Read more

    96 customers mention90 positive6 negative

    Customers find the setup process of the router to be easy. They mention that the instructions are clear, and the product is simple to use. Some say that the connections are a no-brainer, and that it can connect to a separate wireless router if desired. Overall, most are satisfied with the ease of setup and use of the product.

    "...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..." Read more

    "...was really easy to set up and had all the information on how to install to my charter account...." Read more

    "...Works great, set it up its pretty easy , just call your cable company to register the ESN and that's it ...." Read more

    "...however the reviews have gone down over time. It started out fine, easy to install and ready to go in minutes...." Read more

    82 customers mention70 positive12 negative

    Customers generally like the value of the networking router. They mention it works great, is relatively cheap, and has saved them serious cash. Some say that it has lowered their monthly internet bill.

    "Greate ,Cheap , easy to set up , and works perfect !..." Read more

    "...Easy to setup.Clear instruction manual.Lowered my monthly internet bill...." Read more

    "...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...." Read more

    "The DOCSIS 3.0 high speed cable moden by Netgear was worth every cent...." Read more

    53 customers mention38 positive15 negative

    Customers like the signal strength of the router. They say it's fantastic, great, and easy to install, operate, and understand. Customers also say it works great for 25 Gig internet from Comcast, works with Xfinity 100MBs service, and is perfect for cable downloading to give wireless access throughout the house.

    "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..." Read more

    "...based on condition my modem came in and the fact that it works for Comcast Xfinity internet." Read more

    "...but only one computer could be on line at a time, and then it kept dropping the signal...." Read more

    "In terms of internet quality the device is great...." Read more

    60 customers mention28 positive32 negative

    Customers are mixed about the speed of the router. Some mention that it is great and allows them to stream Netflix and play online, while others say that it's too slow and unable to provide the high speed internet that they are paying for. Some customers also mention that 50% of the connection speed disappeared by the time it got to the Netgear router 3 inches away, and that the WiFi started slowing down.

    "My Unite lasted me for about 3 years before it started slowing down my internet speed. The main reason was heating...." Read more

    "this modem is really my new favorite. works extremely well, no lag, no internet connection problems like my previous arris which was not good...." Read more

    "...chipset has a known issue for causing "buffer bloat", which can result in high latency...." Read more

    "...It started out fine, easy to install and ready to go in minutes. Over time however it has started dropping internet connections...." Read more

    47 customers mention15 positive32 negative

    Customers are mixed about the quality of the router. Some mention it's very reliable, has a strong signal, and has gotten better over their last modem. However, others say that it started failing after a few months, and that it frequently crashes and needs a full factory reset.

    "...It usually works ok, but at night it seems to struggle." Read more

    "...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...." Read more

    "...60;(' The CM400 is a very reliable and sound unit. Bought April 2017, over a year of quality service." Read more

    "...powering up everything was great - shortly thereafter everything was no longer great...." Read more

    84 customers mention6 positive78 negative

    Customers are dissatisfied with the connectivity of the router. They mention that it has a tendency to drop their internet connection, and that it constantly disconnects all devices from WiFi. Some customers also report that the modem frequently refuses to connect to the web at all. Overall, customers are disappointed with the product's connectivity.

    "...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..." Read more

    "...Over time however it has started dropping internet connections. It loses connection and will sit idly for a few minutes before it decides to pickup..." Read more

    "...Our wifi signal was kind of weak but we were still able to use it." Read more

    "...out of the box set up easy but within 24 hours started constant cycling to find connection...." Read more

    19 customers mention4 positive15 negative

    Customers are dissatisfied with the heating of the router. Some say that it runs hot and can't maintain internet connectivity. Some customers also mention that the modem gets much warmer than any internet device should.

    "...The main reason was heating. These modems gets very warm and needs to run 24/7 there should be cooling units to make them last." Read more

    "...EDIT: Strongly suspect this one is prone to overheating. It’s very small and not particularly well ventilated, and felt very warm constantly...." Read more

    "...However, it does run rather hot at times, and down here in Texas that can be rather detrimental to the operation of the device...." Read more

    "...Haven't checked into this too much, but it seems like this Modem generates less heat than my old one did as well. A great value!" Read more

    Just that it works
    4 Stars
    Just that it works
    The unit is what I needed
    Thank you for your feedback
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    Top reviews from the United States

    Reviewed in the United States on August 8, 2016
    Size: DOCSIS 3.0Verified Purchase
    Reviewed in the United States on April 28, 2017
    Size: DOCSIS 3.0Verified Purchase
    2 people found this helpful
    Report
    Reviewed in the United States on December 22, 2015
    Size: DOCSIS 3.0Verified Purchase
    One person found this helpful
    Report
    Reviewed in the United States on January 17, 2023
    Size: DOCSIS 3.0Verified Purchase
    Reviewed in the United States on June 16, 2017
    Size: DOCSIS 3.0Verified Purchase
    43 people found this helpful
    Report
    Reviewed in the United States on October 21, 2015
    Size: DOCSIS 3.0Verified Purchase
    3 people found this helpful
    Report
    Reviewed in the United States on December 20, 2014
    Size: DOCSIS 3.0Verified Purchase
    2 people found this helpful
    Report
    Reviewed in the United States on December 1, 2023
    Size: DOCSIS 3.0Verified Purchase

    Top reviews from other countries

    Zahar Alexandru
    5.0 out of 5 stars Great product, but not for EU use unfortunatelly
    Reviewed in Germany on October 1, 2021
    Size: DOCSIS 3.0Verified Purchase