Motorola Cable Modem, from 1,000 Mbps up to 6 Gbps Max Speed. Approved for Comcast Xfinity Gigabit, Cox Gigablast, and More, Black

Are you looking around in front of your laptop for the best Motorola Cable Modem or at least a good deal of Motorola Cable Modem? Well, look no further and you are just in the right place. We are very glad to do what we can to save you time searching around the web for the best products or daily good deals. You do not have to spend much time choosing your favorites from a wide range of products yourself, we do it for you! We always work hard to find almost any good deals and probably for your best choice, and carefully curate an article for that in order to present you the information needed including specs, pros & cons, and customer reviews & satisfactions. What are you waiting for? Let's check it out!

No modem rental fees. Ultra-fast, reliable Internet.Family using Internet connected devices.

The smart choice for your cable Internet service

Eliminate monthly cable modem rental fees – Typically saves 156 dollars per year in Xfinity cable modem rental fees. Actual savings depend on your service provider.

1,000+ Mbps – Maximum actual Internet download speed

GigE Ethernet port – For a high-speed wired connection to any router, computer, or other Internet-capable device.

MB8600 cable modem shown with a WiFi router

Connect any WiFi router you choose

Plugs easily into any router for shared Internet access by all your WiFi and Ethernet-capable devices. This flexible approach lets you pair this cable modem with any router you choose for your WiFi needs, including a mesh router or gaming router.

If the MB8600’s Ethernet port isn’t used for a router, it can plug into a computer, HDTV, game station, or other Ethernet device.

Certified by Xfinity and Cox

Recommended for Comcast Internet speeds up to 1,000 Mbps.

Easy setup with just 3 connections: power, coax cable, and Ethernet.

Compatible with Most Cable Providers

Certified by Comcast Xfinity, Cox, and other cable providers.*†

* Not compatible with Verizon, AT&T, CenturyLink, and other fiber optic, satellite, or DSL services.

† This cable modem does not have telephone jacks for the support of voice calls.

Ultra-Fast Internet Speed

For other service providers, supported service speeds are similar to Comcast.

Easy Setup

Connects fast with just 3 connections – power, coax cable, and Ethernet.

MB7420 product image MB7621 product image MB8600 product image mb8611
MB7420 MB7621 MB8600 MB8611
Product Type (This table only includes cable modems with NO built-in WiFi router) 16×4 Cable Modem 24×8 Cable Modem DOCSIS 3.1 plus 32×8 3.0 Cable Modem DOCSIS 3.1 plus 32×8 3.0 Cable Modem
DOCSIS Channel Bonding 16×4 DOCSIS 3.0 24×8 DOCSIS 3.0 DOCSIS 3.1 plus 32×8 DOCSIS 3.0 DOCSIS 3.1 plus 32×8 DOCSIS 3.0
Certified for These Cable Internet Services. Typically Works with Many Others. Comcast Xfinity, Cox, Spectrum, Suddenlink, Sparklight (CableOne) Comcast Xfinity, Cox, Spectrum, Suddenlink, Sparklight (CableOne) Comcast Xfinity, Cox Comcast Xfinity and Cox
Recommended by Comcast Xfinity for Internet Service This Speed Tier or Below 300 Mbps 600 Mbps 1000 Mbps 1000 Mbps
Maximum Internet Download Speed (Actual speeds are lower) 686 Mbps 1000+ Mbps 6000 Mbps 1 Gbps
Built-in WiFi Router No No No No
Built-in Telephone Port No No No No
Works With Any WiFi Router That Has an Ethernet WAN port
2.5G Ethernet Port

Features & Specifications

  • Top Internet Speeds for all Multi-gigabit Speed Tiers - Wirecutter recommends this model as the best cable modem for people using Gigabit Internet plans. Built-in DOCSIS 3.1 and DOCSIS 3.0 32x8 capabilities give top Internet speeds for all cable Internet services.
  • Save Money - Eliminate up to 168 dollars per year in cable modem rental fees (Savings are shown for Comcast Xfinity and vary by cable service provider.) Approved by Comcast Xfinity and Xfinity X1, Cox, and CableOne for all speeds including Comcast Gigabit services and Cox Gigablast. Not compatible with RCN. No cable modem is compatible with fiber optic, DSL, or satellite services, available from Verizon, AT&T, CenturyLink, Frontier, and others.)
  • Flexible Compatibility - Pair with any Wi-Fi router you’d like, including Whole Home Wi-Fi or Mesh routers like eero, Google Wi-Fi, and Orbi. A 10/100/1000 Gigabit Ethernet port allows connection of any SINGLE device with an Ethernet port including a router, Windows or Mac computer, HDTV, or game station. This cable modem does not have a built-in wireless router or telephone call capability.
  • Proactive Network Security - A broadcom chipset provides advanced security from denial-of service attacks.
  • Active Queue Management (AQM) - AQM significantly reduces Internet latency on both DOCSIS 3.1 and 3.0 services, resulting in faster page loads for all Web traffic and enhanced interactive applications like online gaming and video conferencing. The MB8600 also includes a full-band capture digital tuner to enhance speed and save energy.
  • Dimensions: 7.25 x 2.25 x 7.88 inches
  • Weight: 1.09 ounces

Pros & Cons


With Link Aggregation Group supports >1Gbit/s ISP CDR (hidden feature). Please Read The Friendly Manual of the modem This modem supports Link Aggregation Group (LAG) IEEE 802.3ad -- do not confuse this with IEEE 802.1ax You need to be on a >1Gbit/s ISP CDR with an ISP that didn't disable LAG in the FW / configuration of the modem You may have to remove the cover of the 2nd... RJ-45 -- Please Read The Friendly Manual You will need a router that supports WAN LAG to begin with (the MB8600 ports are 1Gbit/s!) to begin with! You WILL need a router that supports LAN LAG and a corresponding switch for your wired and wireless clients Or You need a router that supports LAN IEEE 802.3bz and a corresponding switch for your wired clients and a corresponding switch. N.B. On "old" WiFi < 5 -- IEEE 802.11ac, et al. -- you may not see >1Gbit/s on your wireless clients On "old" Gigabit Ethernet -- IEEE 802.3ab -- you may not see >1Gbit/s on your wired clients Depending on your machine(s) -- you may still benefit from LAG on the modem side and with the right router -- think concurrency -- even on "old" machines ;) P.S. Some ISPs DO NOT QUALIFY MB8600 DOCSIS 3.1 Cable Modem for their >1Gbit/s plans -- still works (FingersCrossed)

Game Changer. Previously had Arris Surfboard which was part of the list with Wow wifi, however it lagged most times with light use. I thought it was the server itself until discovering that the modem had a well known defective chip causing the slowness, especially when loading Youtube TV etc. With this Motorola the speed is night and day, not even close, and no issues at all. I can't believe after a few years of thinking it was poor wifi that all I needed was the proper modem. I researched many modems finding this to be the best priced along with speed. Another choice I made was deciding to have separate equipment with a modem and router, which maximizes performance as well as only needing to replace 1 item if need be. So much better than the modem/router combo units. Also, works perfectly with one TP-Link Deco AX3000 WiFi 6 Mesh System Deco X55. I did a ton of research on all this since I'm not super techy, but this was the way to go.

Pretty easy to install on Cox. I moved from an Xfinity territory to a Cox territory, and due to the hassle of moving waited around a year to bring over my old equipment, which was a SB6183. I tried activating it on Cox's network only to have to call them and eventually find out that that modem did not support my new speed tier. That meant either continuing to pay $12/mo for Cox's gateway (which we only used as a modem anyway), or buy a new modem. On cross-referencing Cox's compatibility list, I decided on this modem due to reviews and such. It wasn't as easy to activate as other modems have been in the past - on Xfinity, it was just plug modem in, power cycle, an activation page would pop up and I was good to go. With this I had to call Cox - not that it was a big deal but then I had to read MAC and Serial info over the phone, took about 10 minutes, but honestly this is probably just an issue with Cox and not with the modem.

Modem with Google Nest Wifi Router. I wanted to smash something when I tried to get this modem to work with my nest wifi router. So read carefully if you want to save hours of frustration. When you activate this modem, DO NOT connect the Ethernet port to anything. Let the modem activate and boot up fully to see all the lights. After that do you start connecting the Ethernet to the Google nest wifi router. If the router still doesn't connect, then you may need to reset and re-add your router and points. Other than the setup, once it was working, I did get the speeds I was hoping for with Xfinity.

Simple Modem. Check your ISP to see what Modems work with your ISP. This modem was recommended. When I received it, I was told that I had to call Xfinity to activate. That process took the better part of an hour, at the end of which, she said it was activated (she was difficult to understand due to her heavy accent). I couldn’t get my external router to connect. Tried connecting to the LAN with my laptop. Nothing. Called Xfinity again. A gentleman with another heavy, hard to understand accent worked in the issue. Said the modem was activated. Still couldn’t connect to the internet with a LAN cable. Finally, I reread the instructions - which said to use the Xfinity app to activate. That worked beautifully. Wish I’d been smart enough to just do that at the beginning 🙄.

Lighting fast delivery, expect it to last for years. Have to admit, I was impressed. Ordered before going to sleep, and arrived by lunch. Can't fault "instant" delivery as this was just as quick as going to the store. Moving to the modem itself, Motorola has always been a reliable model, serving me well for decades. The new Motorola MB8611 has already fit seamlessly into my computer network. The backside plugs are well marked and simple to use. There is an included wrench for the main cable, but it really isn't necessary. I also like that it has an independent power button vs the plug/unplug option of older models. There is even a recessed factory reset option marked in red, should it ever be needed. It too longer to get Comcast to update my account with the new data than it did to unbox and set up the new modem. With lots of room to "grow", I expect it to last me for the rest of the decade without any drama.


Issue with getting Motorola product support. Unit was very easy to install and set up. I have had this unit for approx. 4 months. Was working very well until the last 3 weeks. We started dropping the internet signal intermittently . It would reboot automatically. I contacted Xfinity about this issue since they are my provider. They were very good about trying to fix the issue. They installed a signal monitor for several days and found that it was a problem with this modem. It has a 2 year warranty through Motorola. At this time I am having some difficulty reaching them for support. Hopefully it will get replaced. Wanted to add some info: I had contact with motorola support. I had to send them reports from the modem. They told me that some of my bonded channels had too much power and was out of range for the modem. my internet provider had been to my residence and placed a signal monitor on for a few days after checking that all connections were good. It showed that the signals and power levels were all within their parameters. My xfinity tech sent me the report which I sent to the motorola tech. I was wanting them to replace it and I would try another unit but now I am just stuck with the Motorola tech saying that their equipment is fine. In my opinion, the motorola equipment is built with too tight of tolerances. They really don't stand behind their product. I was asked for an opinion about the service I received from Motorola. I explained everything that I have laid out here and have received no response. Just thought I would put this out there so everyone else would know. Buyer beware. I will now have to look for another modem since this one just keeps dropping at random.

Bad MB8611 - Moto no longer infallible. The first MB8611 I received was bad modem and it was difficult to diagnose the problem. I would get intermittent drop out and the modem would reboot itself 6 to 8 times a day. It became impossible to watch a movie on Netflix and Amazon Prime Video without interruptions. Originally I believe the problem lied with Comcast. The cable company kept insisting there wasn't a problem with their line and resisted sending out a technician. I put up with the lousy internet service for three months making repeated complaint calls of drops and low speeds to Comcast. Finally, they sent a cable tech out and replace the coaxial cable from the pole to the home because they did notice power levels were low with the upstream. With the new coaxial cable install did improve speeds, the drop outs continued. To add insult to injury, Comcast raised by monthly rate per month and basically strong-armed me to accepting a 800/mbps service for seventy four dollars or keep my existing 200/mbps at one hundred a month. They did not give me the credit for the lousy service I experience for the three months prior to the new coaxial install. I was ready to ditch Comcast for T-Mobile 5G Home service which recently became available in my area. Anyway, I really believed in the Motorola brand and I refused to believe it could be the modem. I owned Motorola modems since the DOCSIS 1.0 days in the early 2000. After searching the web for information regarding the MB8611, there were many complaints about this new modem. So I decided to give Comcast the doubt and ordered a second identical modem. I did so because I really wanted to keep the 2.5Gbit ethernet connection so when the time comes, I can replace my current Ubiquity's Edgerouter X with something with a 2.5Gbit wan port. To my surprise, it was indeed the first MB8611 modem. The new modem did not drop or reboot for two days as of the time I am writing this review. I checked the modem's internal log and connection status to make sure there hadn't been a problem when I wasn't home or at night when I was a sleep. So far, zero incidents. I hope the problem doesn't reappear after I finish this review. Fingers crossed. Long story short, if you experience repeated reboots and intermittent drop outs then consider it may be the modem. Have your cable company do their thing and check the line first to rule that out. If the problem does not get resolved then consider exchanging your mb8611. You might have just gotten a bad one like I did. The second one is solid so far. I am happy I purchased from Amazon because they saved me a lot more aggravation if I had to deal with Motorola's support line. Apparently a company called Zoom Telephonics actually manufactures this modem under the Motorola brand name license. So these modems are not the rock solid modems from the early Motorola generation many of us have become accustomed. I took away two star for the hassle caused by the modem and the aggravation of having to deal with Comcast automated voice hell system to reach a real human every time I had to call them. Of course Comcast could have easily told me it was the modem but refused to look at it since it wasn't company equipment. It was customer owned equipment. I had to hear the same sales pitch on the phone and by the technician as to why I should be using their company's modem instead of owning my own. uh huh, I'm not going to pay a monthly modem rental fee Comcast!

First unit was bad and rebooted every hour, replacement unit seems ok. Received the first unit and set it up, activated via Xfinity with no problems. However the new Motorola MB8611 cable modem kept losing connection and rebooting every couple of hours. The previous modem was an Arris SB6183 which had been performing fine and was up for 110 days (according to the web interface) before being replaced so there was no problems with the cable signal. This older model was only replaced to take advantage of speed increases in my Xfinity internet service - not because there were any problems. Replaced the non-working Motorola MB8611 through Amazon and the new one arrived and has been working reliably for about a week now with no drop-outs or reboots. Web interface shows it to be up continuously for 7 days. So I'd have to assume the first unit was defective. Not sure if I just got a lemon or if there's some underlying problem with the design. Hopefully the replacement will continue to function reliably. Overall it turned out to be a frustrating experience.

Yours might not be new. After spending 2 days -- 1 of them with a tech at my house -- trying to get mine working, it turned out that the one I was sent was NOT new. It had been connected to somebody's ISP account before and was never officially removed, which meant it could not be connected to my account with my ISP. It looked new. Was in the shrink wrap and everything. But it was a used unit. Be careful.

QA issues. I decided to upgrade Comcast speed and it turned out that my old modem "did not support" higher speed. NOTE: despite everything what I've heard ild modem showed speeds above "limit" during my troubleshooting. So, I ordered this one, quickly received, installed, and... Month long story started. The speed was barely approaching the speed of the older modem. With time I observed brakes in Comcast service, but I thought OK - rains, maybe maybe these brakes can be explained. But "no service" became more and more often. As after reboot of the modem service recovered every time, I started suspecting the modem instead of Comcast. In last days I was still tolerating the new modem the breaks in service were happening every 3-4 hours. Thanks to excellent Amazon's return policy I returned the modem and replaced with the same one (due to very high flying reviews). The replacement works fine (for now). What's good? 1) Amazon return policy 2) Now modem fulfilled all expectations I gave 3 stars instead 1 because it works fine after all...

Not compatible with Xfinity. Product said it was compatible but I spend 3 hours on the phone with Xfinity tech trying to install this modem finally I gave up they said they would send a tech out but I figured it was easier to just return the item. Can't comment on the unit cause I couldn't install it.

Why Online?

When you are looking for product reviews or product information like features and specs before you take an action to buy it, you may see similar things here and there that major online stores top the list. Why so many people prefer shopping online?

Nowadays, being with digital stuff, people can have more options in a more intutative way easily by internet, no matter they use pc, smartphones, or tablets. Buying Motorola Cable Modem is just a piece of cake if you go for online shopping that you could do shopping anytime you wish and you could easily make a cancellation if you find it not good as expected.

You can view all brands easily online for the product Motorola Cable Modem before making a purchase. You can also make a price comparison with only a few clicks or touches, then sit down and go through the details while enjoying your cup of coffee. In other words, you can save money and time by shopping online.

Furthermore, you can grab good deals or even amazing deals at a very low price now and then if you go shopping online.

Aspects You Should Foucus on When Buying Motorola Cable Modem Online

Is Motorola Cable Modem urgently needed? Well, shopping online requires some research that you need to ask yourself some questions. To help you with that, we cover all the important ones and put up a list.

Go through the following list and feel free to do your own research while buying the Motorola Cable Modem.

  • Is the Motorola Cable Modem worth the money?
  • What advantages and disadvantages does it have?
  • Does the Motorola Cable Modem you choose have any eye-catching or leading features?
  • What are the features or specs of the Motorola Cable Modem that make it outstand?
  • Does the Motorola Cable Modem come with a warranty?
  • Does it have any cons or defects that existing customers have found out?
  • Where can you get enough information for Motorola Cable Modem?
  • Where can you get the best Motorola Cable Modem?

Easily, you may come up with more questions than those on the above list, just ask yourself. Research and then research again, until you get the answers or you are satisfied with it.

Benefits of Shopping Online

There are many benefits for you to shop online. We have put up some for your reference when shopping online. Let us see what benefits online shopping offers:

Best Price

Online shopping has been well-known for offering products at the possible best prices. As an online platform, it cooperates with many dealers, manufacturers and sellers to offer daily good deals directly, which leaves no room in the middle and reduce additional cost.

Easy to Compare

You can easily do a product comparison at many online shopping websites at a time, casually and relaxably at home. With the ratings, you can decide which product should be your choice, which allows you to have better experience than that of traditional shopping.

High Reliability

Online shopping is reliable since customer reviews are posted directly, no matter they are good or bad. With customer reviews, there is still room for you to make a decision if you found any cons of the product in customer reviews.

Great Customer Service

You can receive best ever customer service from online shopping because competition is too fierce, which makes you feel very good to shop online.

Large User Base

There is a large user base of online shopping nowadays. Hundreds of thousands of people go shopping online these days, especially after the pandemic, people are more likely and willing to do that than driving to stores.

Vast Variety

You can have a vast variety of products to choose from if you go shopping online. If model A / brand A does not meet your requirements, you can easily turn to model B / brand B, or any other you like, which makes online shopping flexible.


No specific location, time or transportation is required for online shopping. Instead, all you need is just a pc or a smartphone with internet connected. Online shopping is so convenient that you can sit down enjoying your cup of tea or coffee, make your choice and pay it with just few clicks or touches, then wait for your delivery.

How to Choose Your Motorola Cable Modem

First of first, you need to follow a brief guide as follows in order to buy something like the Motorola Cable Modem. So let's go through the check list before you take an action.


First, check the price tag for a possible best deal. You can make a price comparison between different sellers or platforms and choose the one that you are satisfied with.


Second, before you buy the Motorola Cable Modem, you should take the brand of the product into account. You may learn to seperate the products for different brands to make a right decision.


Third, a warranty is a must for the Motorola Cable Modem. Nobody likes to spend money on anything that does not last long, right?


Another thing to check for your Motorola Cable Modem is functionality. You can accomplish that by checkcing the features and / or specs. The more features / specs you see, the more functions your Motorola Cable Modem could offer.


Moreover, you must check the dimensions for your Motorola Cable Modem because wrong size may result in wasting time and money. It is highly recommended to learn about the dimensions of the product before any action.


In addition to the above, you should check the color for your Motorola Cable Modem as well. Does it offer color options? Do you like the color of the product? Then check if the color you have selected is available.

Existing Customer Reviews

The last thing to check is customer reviews. No matter how many the features are, no matter how powerful the specs are, you must verify that by lookig into existing customer reviews generally listed right after the features and specs, or before the bottom of the page. See what they say about the products, how they feel and probably an update after one or two months' use. Finally, make a decision to buy or not to.


This is a basic wrap up for buying Motorola Cable Modem online. We hope you will find this helpful. You can follow this shopping guide to get the possible best deal for your own online.

Furthermore, you can do more research yourself to learn more about the best Motorola Cable Modem. If our shopping guide helps you, please share it.

Wish you get a great deal!

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