Motorola MB8600 Product Details
The Motorola MB8600 is a DOCSIS 3.1 cable modem certified to work with Comcast Xfinity, Comcast Business & Cox services. This model features 32×8 channel bonding, and is backward compatible with previous DOCSIS versions, allowing you to upgrade and future proof your network without worrying about compatibility with DOCSIS 3.1.
Motorola MB8600 Compatibility & Speeds
MB8600 is a DOCSIS 3.1 Cable Modem certified by Comcast XFINITY, Comcast Business, and Cox Communications. Owning your modem can save you $132+ per year in cable modem rental fees. This means that after just a couple years, this modem will more than have paid for itself with the savings you’ll be receiving. MB8600 supports ultra fast DOCSIS 3.1, the only cable modem standard that can deliver Internet speeds of 1Gbps or higher, up to many gigabits per second, so you can bet that this device will last you for several years to come.
Motorola MB8600 Speeds
Additionally, the MB8600 modem has 32×8 support for the fastest possible speeds using the DOCSIS 3.0 standard. Even if you don’t have DOCSIS 3.1 service now, you can benefit from the 32×8 DOCSIS 3.0 capability that’s also built into this cable modem. This offers you gigabit+ speeds and future proofs your network for the next 4-5 years as cable companies upgrade their services to meet increasing demand for higher speeds.
MB8600 Additional Specs & Features
MB8600 provides high-speed Internet for a computer, router, HDTV, game station, or streaming media device. Plug in any wireless router to add WiFi connectivity to your network instantly. The MB8600 features low latency, for the fast response needed for many online games. This model also includes 1 open Ethernet GigE LAN port which can be used to connect a WiFi router or other wired devices.
It includes DOCSIS 3.1 Active Queue Management (AQM) which speeds page loads, gaming, and video conferencing. DOCSIS 3.1, 3.0, 2.0, and 1.1 support and Cable Labs certification ensure compatibility with services nationwide. Setup is fast and easy with our Quick Start guide. ModemGuides experienced USA-based support specialists are ready to help.
What’s Included:
- Motorola MB8600 Cable Modem
- Ethernet Cable
- Power Supply Cable
- Online Installation Manual
Will this work with my internet company?
This Motorola modem is primarily used and is compatible with Mediacom, Cox, Comcast, Spectrum, Charter & Time Warner service in most areas. To verify that this model will work in your area, always contact your service provider’s customer service prior to placing your order with us to confirm that this model will work with your service plan. Some service plan speeds may not be supported.
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Arris Routers
Filip Hanik –
Update August 16, 2017:I ordered another modem to see if the commenters of my review that were hinting at a user error were right.This modem got connected within 5 minutes and I got a public IP through DHCP from Comcast. Activation worked fine.I did get a dead on arrival modem the first time. I guess the quality check in production is not quite there.I will run this for two weeks and report back.PS. the ports labelled LAN ports are not LAN ports, they are ethernet ports. The is no internal network on this modem.Update June 29, 2017:Many comments on my review. Let’s be clear about the rating it got.1. The modem received a rating of 1 star because it didn’t work out of the box. That is expected.2. The modem would have received a better star rating had it worked.One gentlemen commented that he had to install a configuration file himself in order to make it work with Comcast. Instructions for this is mentioned in the documentation nor was I able to verify this online.The irony of naming 4 ports LAN, as in Local Area Network, seems to fall short on some angry commenters. These are not LAN ports.https://en.wikipedia.org/wiki/Local_area_networkOriginal review:Signal connects fine to Xfinity/Comcast over 1Gbps, but I don’t receive an IP address. We tried three different devices. Comcast tech device, Apple Macbook Pro and ASUS Router.You will not get an IP address over DHCP or any other protocol, external nor internal. You can connect to the modem directly to check the status but you will not find out anything. The web interface is completely useless. Nothing is exposed. It’s like half the model is missing in hardware and software. At this price point, I’d certainly hope the modem would do a bit more than just modulate a signal over four ports.I would not recommend this modem. While Comcast will work with you to make it work, there is nothing they can do if the modem itself doesn’t work. We had Comcast try this modem and declared it non working. No external IP is received. Our tech spent 30 minutes and then finally gave up. The Comcast provided modem connected in 5 minutes.You can tell this is a brand new product. There has been no effort creating a working interface when you login to the modem. Nor does the documentation help you with expectations.UPDATE JUNE 10, 2017I had two gentlemen comment on this review saying that the modem doesn’t have any router functionality what so ever and that a separate router was needed. I stand by my 1 star, because this product is sold as a consumer product, and one without documentation. To claim that a device with 4 internal network ports doesn’t have routing capabilities is a bit naive. So instead we have a four port switch on the back. While two of them can be used to bond two ethernet cables together to achieve over 940Mbps download speed, documentation says that any of these ports should work if you just want to plug in a single computer or a router.1. The modem has absolutely no documentation, for a consumer product this is somewhat surprising, If the modem should not be used for routing at the layer 3 IP layer, then how should it be used? Clearly the modem acts like a signal switch and nothing else. For this price point, a bit more functionality can be expected.2. The modem provides 4, not one, but four Local Area Network connections. The sparse documentation even calls them this.That those connections would provide some very basic IP capabilities. What kind of Local Area Network connection would this be if I couldn’t do basic routing. Why are these ports called LAN ports, if they are actually WAN ports. These ports do NOT separate you from the WAN. In fact, in the expected setup, you’d have a WAN IP address. Maybe my terminology is off, but in most environments I’ve seen, a LAN is separated from a WAN by using a private address range in the LAN. One would have hoped that the modem provided this very basic capability.3. My home routers will support different types of WAN connections. Static IP, DHCP, PPPOE, PPTP, L2TP. If the modem doesn’t support the two first IP based protocols based on Ethernet, the document doesn’t even mention any other. This alone makes the product not ready to be shipped to anyone.Should I have tried one of the other three protocols? If so, which one? The product gives you no guidance for how it is supposed to be used. I believe Comcast just dishes out IP addresses over DCHP in its simplest form. But we’re not able to confirm that. Modem didn’t workFrom a consumer stand point, this product is not ready to be used. Lack of documentation and lack of user interface from the 192.168.100.1 web server, makes it, once again, totally useless.
Responsible User –
Pros: Runs great, uses Broadcom chipset. Small. Reasonably priced. 32×8. Modem admin name is changeable. Can do up to 4 bound ethernet ports for 4gpbs if you can afford it. LEDs are not bright, and only the ethernet one blinks occasionally. Comes with a wrench for tightening coaxial heads.Cons: Instructions say to go to xfinity.com/internetsetup but it doesn’t load, you actually want /activate. Before realizing this, I tried to activate remotely from my xfinity account and it said activated, but it wasn’t.Overall opinion: There is no competition right now.
Eurodude in NJ –
Love this modem so far. Runs very stable so far and also runs much cooler than my Arris SB8200. Also like the built-in surge protection. Easy to activate on Comcast network via automated walled garden method (i.e. no need to call Comcast support). Getting 29 actual (locked) downstream channels (1 of which is OFDM) and 3 upstream channels. Download and upload speeds measured with speedtest are above my tier and more importantly are consistent with no disconnects so far (up almost 2 days – just bought it). It also passed the Puma 6 and Line quality tests (dslreports site) with flying colors (note – this is not a Puma 6 modem, do not worry; however it can still run the test). Also love the power button which the SB8200 lacks.
AR –
At first I thought there was a problem with this modem because I was only getting 130 mbps. That speed was the same I was getting on my last modem. I tried calling Comcast tech support several times. They couldn’t figure out why my speed was so slow versus what I was paying for (1 gbps). Finally, they sent out another tech to look at all the connections leading to my house. The tech rewired and replaced some things. We ran the speed test again and still got 130 mbps. So, I ran the speed test on another pc in the house and achieved 830 mbps. After the tech saw these results he figured he did his part and left. I went to the first pc I ran the test again to figure out why the speed was so slow. What I found was that there was a setting on my NIC that was the issue. I changed the setting and now I’m getting speeds anywhere from 830 to 930 mbps.Update: Just did another SpeedTest. Achieved almost 950 mbps!!! I added a screen shot of those results.
DC James –
Great modem! Getting fantastic speeds on Xfinity with gigabit service.
Jacob –
connected pc directly to modem and did the activation online. super fast activated on comcast in under 5 min. after i activated the modem i connected my router and away i went. internet now is more snappy. i moved from a zoom 5341h(4×4 modem)im on the blast tier and am seeing 230 meg down x 13 meg uploadsignals on my older modem were at +1 power on 4 downstream channels with an snr of 37upstream power stayed the same. as you can see with attached picture my snr greatly improved with this modem.
BR-549 –
I would have given this a 5 star if I could access the administration web interface. I was briefly able to access 192.168.100.1 before my ISP (Cox) blocked port 80 access probably in part due to their special firmware update. I’ll post a snapshot of what I was getting before it was blocked. I probably can’t blame this on Motorola, but I have seen Arris products provide some of these stats that would be useful in troubleshooting cable problems before calling out a repair that might be an inside wiring problem. I’m getting excellent throughput approx. 250Mbps/10Mbps and I can tell both down/up are being throttled back. Anyway, I’m ready for DOCSIS 3.1.
cmlusco –
Sleek and future ready. It looks great and was easy to hook up and activate with Comcast. Since its DOCSIS 3.1 I can now upgrade my seevice to the 300mb speed they already offer, and the 1gb speed they plan to offer in the near future.
USAForensic, llc. –
I started out in the 80s with a 1200 Bauer modem… so things have come a long way. This with a good multi antenna wireless transmitter is a solid combination, the chipset and 3.1 is above what Cox offers in their modem selection. Lights aren’t obnoxiously bright at night :)A solid offering by Motorola. Easy to configure.
J. Jenkins –
Purchased this to replace my rented Xfinity (Arris TG1682G) modem, and got it going today with a bit of help from Xfinity technical support. This device doesn’t have WiFI, so I also purchased the Motorola MR1900. The transition to the modem was relatively painless… As I mentioned, I had to call Xfinity for technical support to complete the transition, but they were able to make it work. I still have to return my rental to stop getting charges, but the switchover is something I should have done years ago. The Motorola products are solid, fast and full featured for everything I need to do – so I couldn’t be more pleased.
Brad –
Not as advertised. It does not have four ports, the one they sent me only has one. Check out the pictures.
Umie –
I switched over 3 months ago and the modem is still working well and is allowing me to max out the output to my Tri-Band EA9500 router
Brent J. Calvin –
Bait and switch. In the time it took to order this item they swapped it out for a version with a single port.
Customer –
There are four ports on this unit. Even though the box and the unit look to only have one port there is a sticker covering the other ports. After having the technician at my house for three hours the other ports that are being covered are completely useless . When attaching a cable to it it will not fix to IP address is so either it keeps the first keyboard connected or it connects the IP address to the second cable and you lose the first connection.
mal –
Working well so far. Haven’t tried bonding, but there’s a checkbox in the web interface for it. The new product photos show only one port but on mine the other three were just covered by a sticker.
BATL –
Love this thing. I don’t buffer anymore when watching 4K Netflix and everything is super responsive. The setup was really kind of neat and did it totally through the phone login service with the Comcast internet service. As advertised, I did just plug it in, had the initial boot-up (took about 10 minutes) and log in. Then good to go. Don’t forget you may need to restart your router/AP’s after. Came from a very old DOCSIS 3.0 modem and the new one picked up on the 3.1 DOCSIS connection (Blue indicator light).
ATTICUScc04 –
Bought this modem to use on Grande Communications 1gig service here in Texas. Easy to setup and works perfectly. Getting about 950 download and 53 upload. Graphical Interface is kinda buggy sometimes when you log in, but I’m sure that’ll be fixed with a firmware update. Not really a big deal anyways. There is a sticker covering the 3 ports on the back, so it may look like it only has one. Using this with a ASUS AC88U wireless router and it’s blazing fast. First time using a Motorola modem. I’ve always used Netgear and decided to switch it up. No complaints so far.
Customer –
Seems to be working OK for now.
Gregory –
Boss modem.
Adam –
This didn’t work well. Kept dropping the internet connection and we replaced it with an Xfinity device. After that, no troubles, so it had to be this modem. Might have gotten a bad one. For the price, they should work!
oymehoy –
Super bad experience. We have to reset the modem at least 5 times per day. I’ll not recommend this to anyone.
DP –
I got this to replace Comcast provided modem. I have had it about 6 months no problems at all.
Roy Daly –
Avoid this at all costs! Bought this after Comcast said I needed to upgrade my 7 year old Surfboard modem. This modem drops the internet connection for a few minutes each time and multiple times a day. Maybe a firmware update will resolve the issue but I will be trying to return and hooking the 7 year old modem back up.
Digital Nomad –
Want to save the $10/mo from Comcast? Buy this one. It’s on their approved equipment list. Too bad Comcast’s “representative” boldface lied to my face and told me they had to provide the equipment to get Gbit service. Seriously, what’s with that company? Anyways, aside, this is a great product, and we’re pushing about 800mbit on a gig service from Comcast on it (the tcp/ip makes this around normal). This was a quick call to activate and works very, very well.If you’re looking for a solid product, this is it. Been working non-stop since we plugged it in, and has been rock solid with no reboots or problems.
Mike Smith –
The setup went well, but luckily I was interrupted after I first plugged it in and had no Internet on the laptop I was plugged into as instructed. When I returned I watched the lights on the modem which like before, showed that it was connected to the Internet and data was flowing in and out. Then suddenly while I was watching it, the modem reset itself and when it came back up totally then I DID have an Internet connection on my laptop. When I went to yahoo.com I was redirected to the xfinity page and following those instructions and I successfully activated the modem.The moral of the story, don’t give up right away if the modem appears connected but your laptop has no Internet. Comcast apparently detect that you have a new modem and does something to initialize it. I now have the full 150 mbps download working which is what my plan is. I am very happy.I should add another minor point. Other reviewers described 4 Ethernet ports and mine only had one. I rechecked the model and it was correct so they didn’t get my order wrong, but when I looked again there is long piece of peel-way vinyl covering all the ports but one. Since most people can only use only that one port they apparently cover the other ports so you don’t even know they are there. Smart, but initially confusing.
Steven Rash –
Got the e-mail from Comcast saying it’s time to buy a new modem. Wanted to be sure to buy a 3.1 so I’m future proofed. Set up was quick and painless. Visually appealing on my home entertainment center. The LED lights aren’t too bright or distracting. ** BE SURE TO READ THE PRODUCT DESCRIPTION re: the 4 ethernet ports – they are there for FUTURE USE. This is NOT A ROUTER.
Customer –
Started crapping out after a few months.
john –
works well thank you
Carlos –
No issues whatsoever. A solid cable modem that continues to work reliably day after day.
Elector –
Works great, fast delivery. Amazon is amazing and their sellers are too. This is compatible with Comcast Xfinity.I got a private modem when I learned Comcast was making public hotspots from its customers’ modems without our informed consent. Then they sell the wifi service from our units to ‘on the go’ roaming customers.Here’s what happened when I returned my rented modem to Comcast. They said I had to continue to be charged the modem rental fee because this modem doesn’t have a phone jack. The Comcast staff cited FCC rules. They couldn’t produce the claimed rule and I had to go through 2 managers before it was finally admitted to that there is no such rule. I hope nobody else has to fight for an hour to avoid the rental fee for a modem you don’t even have. This modem is compatible and IT DOES NOT NEED A PHONE JACK FOR THE MODEM RENTAL FEE TO BE REMOVED WHEN YOU TURN THEIR MODEM BACK IN.
dougiestyletone –
I have owned this modem for about 8 months and must reset it every day to get the advertised speed (300mb/s) from Cox Communications in AZ.Not a great experience.
Paul Patterson –
Works great with Comcast Xfinitiy 1GB connection. Speed = 933.7MB Download & 49.6MB Upload.
Bruce –
Easy setup but activated with computer before switching to router. Excellent speed, runs cool and no dropped connection as with the Netgear N600 it replaced.
Paul Patterson –
Works great with Comcast Xfinitiy 1GB connection. Speed = 933.7MB Download & 49.6MB Upload.
Shello –
My husband ordered this product for a new wireless TV set up. The cable guy came out and got everything set up and it works perfectly. Delivery was as promised.
Sshafi –
Just received what was supposedly a “new” modem, it’s clearly used with none of the plastic packaging or seals. The model has dust on it and the cables are kinked. Certainly not happy about this purchase even if it does end up working (which I’m not certain it will).
Rachael Laufenberg –
Great Modem!*Easy setup*COX gigablast compatible,*Power button on the back*Doesn’t lose connection to the internetIt does what a modem is supposed to do
Rhonda Clark –
XFinity’s website said it activated, but I ended up having to call their customer service. Modem works great.
DJ Ronin –
As advertised. Does the job.
Sarge –
Works GREAT!
calvin roberson –
It is okay, but it does accelerate the game and movie download speeds.
Robert C. –
I’m a Comcast/Xfinity customer. Unplug old modem, plugin new modem. Left the Ethernet cable unplugged until the modem connected. Plug in a laptop directly to the modem, signed into my Xfinity account, and a few minutes later, all done. Once done I turned off the modem, plug in my router and restarted the modem, then turn on my routers and everything connected.
Steven B. –
This Modem is future proof and is wayyyyy faster than the modems the cable providers supply you!! I have the 300 Mbs/s speed and after installing this beast I get on average 487.96 Mbs/s!! Don’t think about it, just buy it!!! You will not be disappointed.
Michial D. Lowe Jr. –
I am a Spectrum customer and was a bit hesitant about purchasing this modem at first…and well my hesitation was rather pointless. Once the modem arrived I hooked it up, contacted Spectrum and let them know I’ll he using my own modem for service. They asked for the modem MAC address and some other questions. And within about 10 minutes time I was online and enjoying myself. To date I’ve had zero issues with the modem…but then again I’ve never had an issue with a Motorola branded modem. I am also seeing higher upload and download speeds than what I’m paying for, which is a plus.
Had –
So far so good with connectivity. It is a lot bigger than one would expect and didn’t fit on my electronics shelf. Bigger than most modems and doesn’t set well on its side.
Conscientious Consumer –
This modem didn’t work correctly from the time I bought it. It constantly knocks me off the internet. Judging from other reviews, this is not an isolated problem.
DevinRhode2 –
If yo uget 3 solid blue lights (up/down/net) you should be good even if your cable provider doesn’t say so..
CFortC –
Comcast/Xfinity had sent me a letter warning that my current modem (Cisco DPC3008) may not be sufficient to fully utilize my Blast Pro internet service. From the results noted below, looks like my old modem (with only eight downlink channels) was maxed-out.My experience with activating the new modem was painless. A quick online chat providing the MAC, then the service representative sent “Plug away!”. Following an extensive power-up cycle, the modem’s uplink, downlink, and internet connect lights all glowed a steady blue and I was online again.Downlink speedtest increased slightly, from 260 Mbps with the old modem to 290 Mbps with the new MB8600. Latency for some reason increased from 10 ms to 14 ms.Motorola support folks must have gotten weary of responding to all those questions about the four Ethernet ports. My MB8600 came with only one Ethernet port showing, the other three just detectable through the thick plastic film label covering the back of the modem. I guess that Motorola is willing to handle calls asking how to punch through the label if someone wants to use the LAG feature.
Cheryl –
easy set up and use.
BeastyBoy876 –
Worked as expected. I did have to get on the phone with the ISP to help detect and setup the modem. Wouldn’t do it just by plugging it in or by resetting the modem from the ISP’s website. Paired this with a Google WiFi router. So far a good improvement.
Nannoo247 –
Works great. The cable guy was impressed. Just hooked it up. Cable company uses this one for their installations.
Destiny –
Lightning fast, easy to install, I’ve only had to reboot once and I’m pretty sure the reason was because of my Internet provider
Ned –
Was well packaged and in great shape. Modem works fine so far. I’m quite pleased.
Paul D. Pandolfo –
I deliberately waited to review this modem until it had been time tested. Been using it about 6 months now,originally purchased when I switched to cable company Internet service. This one is approved/supported by multiple cable companies, for internet customers want to buy their own modem instead of paying every month to rent, and one of the lowest priced if not the lowest of those listed. The cable guy had an easy time getting it going, and after he left I got it working together with my Netgear router easily to manage my primary and Guest home wifi networks. We had a few power failures and cable service outages over the winter, and I don’t remember ever having to intervene to get the modem to reset. I have upgraded home networking hardware multiple times over the years, and am definitely impressed and happy with this product.
Donald –
Easily and quickly setup between my Xfinity cable and TP-Link WiFi router. Went to the Xfinity activate link as described in the documentation and was up and running in a minute or so. My download and upload speeds are about 10% faster now without any change in my plan. Nice!! This was an upgrade from my Motorola Surfboard Extreme SB6120 which was an upgrade from an earlier Motorola cable modem itself. Good products. If you are running MAC address security on your TP-Link (and possibly other routers, as well) you will need to add the MAC address of this cable modem before activating, even though it is downstream of the internal network.
JULW –
Easy to install and set up. Compatible with my cable company so simply had to call them to initiate service. They were impressed with the DOCSIS 3.1 feature and told me it would support any improvement to download speeds for quite a while.
ry_row05 –
We went from renting a modem from our cable provider to this unit and now our internet constantly drops service and the resumes a few minutes later. I wouldn’t recommend this one!
Gerardo Montero –
1050mbps down no stutters, on 5ghz wifi devices I get about 950mbps down
Dennis D. Collins –
Bought for an upgrade from Docsis 3.0 to a Docsis3.1. After receiving this and installing, the modem would not stay connected.(Ihave Cox high speed internet) Every 10 minutes it would lose connectivity and I would have to restart it. This was very disappointing because I really wanted to like and keep this. I sent it back for a refund. The connectivity issues should be addressed.
uthej –
Well, I have had the modem for about a week now and it has been solid. I have had connectivity issues with COX, but I know that is not the modem (Reason people keep giving 1-2 stars). I have really only had to reset the MB8600 one time so far. Most of the time I just wait and the connectivity comes back. There are several issues for this, 1. too many houses being supported for one area because certain times of the day is when there is a degradation, and 2. the recent switch to gigablast. I don’t think the protocols/provisions are necessarily set correctly since the upgrade. The upgrade just happened within the last couple of weeks. Neighbors keep complaing to COX about it as well. While receiving the Ultimate Service (300mbps), I typically was getting 150-310mbps throughout the house via wifi (depending upon where I am located). The modem seems to be working flawlessly as I have been still getting those speeds. I have just upgraded to the 1 gig service today, so I’ll see how that goes tonight. Hopefully, I am getting close to the 1 gig.
john –
We have had this modem installed for a month now and are very happy with it. We have not upgraded to gigabit yet but this modem is much faster than our previous one that was supplied by Comcast. Installation was very easy.
J. Kuehn –
Had to call Comcast to register it (Comcast’s auto-registration failed), but once registered, it’s fast and rock solid. I’m seeing a 30-40% increase in download bandwidth over my previous DOCSIS 3.0 CM (no change in upload BW). Additionally, the link seems overall more stable (0% packet loss vs 2-4% for the DOCSIS 3.0). Other than being slow to boot and establish the link, I have zero complaints.
Customer –
I’m guessing the 3.1 firmware still is in beta. This modem will lose it’s downstream connection for no apparent reason. Hopefully the manufacturer will find out what’s causing this and work with Comcast to fix the issue. Had ZERO problems with the Motorola DOCSIS 3.0 modem I had been using before this one. It’s not hardware, it’s a firmware problem for sure. Comcast has the 3.1 carrier at the location the 3.0 was, so it’s not a frequency allocation problem.
RONNIE W. WRIGHT –
Terrific price and works out very well, thanks.
Howie Ramone –
pretty quick modem. increased our speed about 20%
D. DeGrand –
Took 5-10 minutes to activate and super fast.
Walking Dead fan –
My old cable modem was causing problems. Found this one was a newer and faster one. Problem solved and I am happy with the speed improvement.
Bob Sale –
This modem is awesome. It made activating Xfinity a very quick and painless experience.
Richard Lenz –
No problems – works perfectly with Xfinity.
Timothy L. OBriant –
When my Comcast service climbed above 250 Mbps, I was encouraged to get a DOCSIS 3.1 modem. Since I’ve used my own for several years, I decided to continue that by getting a top-rated D3.1 modem. I chose this one. I have now used it for about four weeks and I am very satisfied with it. The speed is great and it operates without too much heat. Setup was easy with Comcast. Everything was done online with no fuss.In truth, this modem cost more than I wanted to pay. But, the D3.1 modems are a lot more expensive. For my rating, I didn’t lessen the score because I didn’t like the price. This seems to be an excellent unit that will provide long service.
Phil Stracchino (Technical Thug) –
I’ve been running an Arris SB6121 cable modem for about eight years now, but have been having some outages recently, in which the modem appeared to be at least partly responsible. In addition, the SB6121 is getting old and can support only four download channels, limiting its ability to use higher service speeds now available. My ISP advised that I upgrade, and given that my ISP is rolling out DOCSIS 3.1 starting in November, I decided it made sense to go with a DOCSIS 3.1 modem.Right now, that narrows the choice pretty much to three devices: the Netgear CM1000; the Arris SB8200; and this modem, the Motorola MB8600.The cable technician who just replaced my line advised against the Netgear due to having seen a lot of reliability issues with Netgear cable modems, but had no preference between the Arris and the Motorola. Since their specs are almost identical, but the SB6121 has had some firmware download issues and the Motorola is $30 cheaper than the Arris (and has a two-year warranty), I went with the Motorola. The Motorola, unlike most other cable modems, also has an actual physical power switch, so should you need to power-cycle it you can do so without unpligging it.Both this modem and the Arris have two gigabit-Ethernet ports. Yes, I know, you can only see one in the photos. And you’ll only be able to see one when you take it out of the box. That’s because the second port is hidden under the yellow adhesive film on the back panel.THERE IS A REASON FOR THIS. That second port is NOT for plugging in a second device, and you cannot use it for that purpose. Don’t try. The second port is there so that if your router is capable of it, you can connect BOTH ports to your router and bond the two gigabit channels together into a single 2-gigabit channel. Your router must support this, your ISP must enable the second port,¹ and it’s up to you to configure the router correctly for port bonding/trunking. Of course, this is only relevant if your ISP offers data rates over 1Gb/s *AND* your router can support that anyway. If you’re a residential user it’s unlikely that both of those are true.When you’re switching to a new modem, you’ll need to call your ISP and you’ll need the MAC address from the sticker on the bottom of the modem. You will need to power your router off and wait for the modem to initialize fully the first time before you turn it back on. Expect that first-time initialization to take several minutes. Once the modem is online, bring your router back up and you should be good to go.AS SOON AS IT’S UP, point a web browser at 192.168.100.1, log in to the modem using the default password on the sticker on the bottom of the modem, click Advanced, click Security, and CHANGE THE ADMIN USERNAME AND PASSWORD. BOTH allow you to use only A-z and 0-9, which is a little weak. But you’re allowed up to 15 characters. Use as many of them as you can to make your new password harder to guess — and no, don’t use your dog’s name, your phone number, or a dictionary word as a password. Make sure you record what you changed it to. Don’t lose it.What do you get for your money? Well, in addition to DOCSIS 3.1 support, the MB8600 can bond up to 32 downstream and 3 upstream data channels. In my case, with no change in my service cost, my download bandwidth increased from about 46 megabits per second to about 96.5, and my upload speed from about 4.5 megabits per second to 11. Viewed from the perspective of what I was paying for what service tier, this modem will pay for itself in about a month and a half. With eight times as many download channels, it is also much more resistant to noise or other problems on any single channel.So far, the Motorola MB8600 earns a solid two Technical Technical Thug thumbs up. It is a substantial improvement over the Arris SB6121 it just replaced.____¹ Well, OK, you *CAN* enable it yourself in the advanced configuration on the modem. But if you’re messing with advanced configuration settings, you’d better know what you’re doing. If you don’t, you’re on your own.
Heavysteel –
Hands-down the best modem I’ve ever owned. Lives up to gigabit speeds like so many others claim to, but do not. I have owned a couple of DOCSIS 3.0 modems that claimed they could do gigabit speed’s. Not true! Without getting into a bunch of technical numbers this modem and two other DOCSIS 3.1 consumer models are the only ones that appear to qualify. I can confirm 950 Mbps using Wavebroadband. Speeds will vary depending on time of day, number of users online etc…. The numbers speak for themselves.
Jason O. Grooms –
product worked for two months then quit. Not worth the money.
Heavysteel –
Hands-down the best modem I’ve ever owned. Lives up to gigabit speeds like so many others claim to, but do not. I have owned a couple of DOCSIS 3.0 modems that claimed they could do gigabit speed’s. Not true! Without getting into a bunch of technical numbers this modem and two other DOCSIS 3.1 consumer models are the only ones that appear to qualify. I can confirm 950 Mbps using Wavebroadband. Speeds will vary depending on time of day, number of users online etc…. The numbers speak for themselves.
Customer –
works great
MICHEL ALLEN MYERS –
Running through a TP-Link AC1200. Comcast loaned me their modem to try and get me to stay with their modem. Their modem runs at a full 1 Gb/s on the Comcast speed test. This modem is doing ~600Mb/s. Considering it is rated at 2 Gb/s, I am a little disappointed. I am not disappointed enough to pay Comcast $11 per month. Since their promotion package decreased my bill for the next 2 years by $10 per month, they are paying me $240 to move to ~600Mb/s from 100Mb/s. What is that Don Henley line about too many blessings and not enough appreciation (My Thanksgiving)?
Public Name –
New as advertised. This was necessary as apparently every used DOCSIS 3.1 modem has been registered to Comcast by accounts that are now delinquent.
Customer –
Works great.
Gamer –
Bought this modem because it’s future proof and at a reasonable price. Using this with my old Arris set as the VOIP. Since they don’t offer Docsis 3.1 with phone for the public to buy. Just remember to call your ISP to confirm with your local franchise area… That you can use a NEW modem and your OLD VOIP modem for phone only. Don’t worry either… They will not interfere with each other. Just make sure you have enough power ( Down -5 to +8, UP 38-47) for the splinter.Pros:Good radio, gets 4 SNR better then my old ARRIS. Also less errors.Great shape with lots of ventilation.Boots fast.Good UI.Cons:They removed the spectrum analyzer because of Comcast.
Chicagorex –
I work for Cradlepoint and was provided my own AER2200 router for home use. I had a Netgear all in one cable modem router that I was using for Comcast. I wanted to keep the cable modem separate from the router for isolation purposes. Since I was given a 1200 dollar commercial grade router, I figured I would get the best cable modem available for Comcast. Even though DOCSIS 3.1 is not available, I figure I have that available in the future. It works great and the front LED indicators are straight forward. I went with Motorola since they were the ones who actually developed the DOCSIS standard. Can you go cheaper and get the DOCSIS 3.0 unit? Absolutely. If you want to spend a bit more and perhaps delve into channel bonding in the future, this is a good option.
dawg74 –
it reduced my internet speed
SAK –
Bought this modem after my Netgear cm1000 failed. Netgear would not honor warranty so no more business from me. I reluctantly purchased this modem instead of the Netgear cm7000 afraid I would take a lose on my downstream/upstream data. From the point of opening the box I began to see that the Motorola was definitely a way better purchase. The modem itself is very durable feeling. Setup was a very easy. I’m actual obtaining equal if not better speeds than my previous Netgear model. So definitely a modem I would purchase again.
John –
absolutely love this modem, way faster than
USWebworX –
Extremely fast speeds now!Doubled my speeds wirelessly as well!
Toyia Williams –
I’ve had this modem for less than 3 months and I’ve had numerous problems with it. Now it must be replaced.
Cody Fife –
Forget that there’s 32×8 channel bonding on docsis 3.0, the speeds offered through broadband cable don’t utilize all those channels due to programming reasons. To achieve anything less than the gigabit service you can easily use a modem that runs with a 24×4 bond, 24 downstream channels and 4 upstream. It’s the 2×2 OFDM MOCA channels that allow a modem on docsis 3.1 to get the full gigabit internet speed which is really 982mbps fyi. Whether you choose this Motorola or the Arris I know you will be satisfied, even the netgear, I just know comcast doesn’t have netgear as a manufacturer of their current rental gateways so I’d steer anyone looking to use their own to look this way. Make sure you get a decent router and possibly a wifi mesh network setup for your home if wifi is important to you. Remember, there isn’t any commonly used device that can utilize a full Gb speed so don’t assume you’re not getting what you pay for, you’re limited by the device you’re using that’s connected to the internet and the connected server you’re downloading from as well. If youre signal says it’s good then youre likely getting the full speed, even I’d you don’t see that yourself.
Geo R –
Don’t know why this modem needs to be reset every couple days. very unreliable. I am using comcast, SB6141 and Sb6183 works perfectly. this modem so wired. just have to reset after a while. I returned and get the SB6183.
Michael W Trumble Jr –
Owned the modem for two months and it worked great the whole time until yesterday. My cable company was bought out by Atlantic broadband and now the modem won’t work. Not a dig against the modem, it works great, but a lot of cable companies aren’t fully supporting it yet. Double check with your cable company’s list of compatible routers first.
Brandon Edling –
I purchased this modem for use with my new gigabit service with Comcast Xfinity. Constant disconnect issues. At first I thought it was because there weren’t any telephony lines and Comcast was trying to provision voice. When it failed, it would be disconnected.I wasn’t using voice, so I took it off my plan… and continued to have issues. I got wise and started researching (Google “MB8600 Comcast Disconnect) and found several others with issues.I decided to buy a Netgear CM1000. Got it set up with Comcast in just a few minutes and it’s been rock solid.Not sure if this is a bad modem, or needs updated firmware, or if the issues happen to be on Comcast’s side (even thought I had several techs come out and check my house’s wiring, all the way up to the equipment on the pole), but the Netgear works as expected and this one doesn’t.I missed the return window and can’t get my money back. Heed my warning; don’t lose money like I did.
John S. –
This modem worked perfectly for 9 months and then suddenly stopped working. Of course, I had to waste hours on the phone with the internet company to find out it was the modem. I would recommend getting a different brand if you have any other options.
Jenny –
Outstanding modem. Works perfectly with Cox Communication. Good strong signal when paired with my router.
Michael Vitiello –
Works well and replaces the modem i rented from xfinity. Setup was easy and xfinity had no problems updating their system to work with my new modem
MF Lynch –
Installation is easy, although it requires a few more reboots than the instructions suggest. So far, no need to touch it again. It’s fast and reliable, and doesn’t generate a lot of heat. And there’s no monthly fee to Comcast!
SAM –
Very good product and very easy to install. Speeded up my system greatly.
JonathanR –
Didn’t last. Started locking up on me and I have to manually reboot it every few hours now.
Chris –
I’ve had it for roughly 8 months, and its starting to drop connection intermittently, but on a daily basis. I’ve ruled out all other possible factors, including the cable, outlet, Comcast’s fault, and the router connected to it. Resetting it does nothing, and restarting it only temporarily fixes the issue. It’s possible that I got a bad unit, but either way, I can’t recommend it.
Descartes –
This was for an upgrade of my former modem. Excellent.
Erckfr –
no more cable rent
cdrikari –
Very solid modem, no issues. That said, despite supposedly being able to be auto-configured by the Comcast website, it took over an hour with their tech support folks to get the thing on their network.
Kingston73 –
UPADTE: I found my problem and it wasn’t this modem. I hope this may help others who are experiencing issues. After investigation I found a 4 way cable splitter where my line comes into the house. I disconnected this and used a coax coupler to connect the two ends of the cable and that cleared up all my issues. Basically the splitter was degrading the signal so much the modem couldn’t function. I’m still only giving it 4stars because I have no idea how it’ll work long term but give this a try if you find issues.I will update this if I find a fix but as of now I can’t recommend this. I bought it to replace an arris 6141 and it worked fine for 1 day. The 2nd day it has dropped connection at least 6 times in less than a few hours. I’m on Comcast and they tried resetting it 3 tomes but it hasn’t made much difference. The arris worked continuously for the past 3 YEARS and this hasn’t managed 3 days yet.UPDATE: the 3 year old “outdated” arris 6141 has now been working fine for hours. The Motorola wouldn’t work for longer than 30 mins at a time. Sending it back, definitely not worth the money or aggravation after spending hours trying to fix it.
ChrisWNY –
Solid, state-of-the-art cable modem using the Broadcom chipset. Works great with Spectrum even though they won’t say it’s supported. Connect your coax line, plug in, then allow the modem to come fully online before connecting a router or PC. The modem will not “bond” with a router or PC unless it’s online first (for the first time). Any time you switch routers you must factory reset the modem before it will bond with a new MAC address. You’ll need to call your cable internet provider and provide the modem’s MAC address so that it’s provisioned on their network.Another note of importance for those who want to access the modem’s Admin UI at 192.168.100.1 – if your network is anything but 192.168.1.x, you may not be able to reach the UI from a web browser on any of your network devices until your router is set up for that particular subnet. I was not able to get to the modem from a 192.168.0.x network, even though I could ping it (on 192.168.100.1) no problem. Motorola tech support stated that they don’t necessarily see this behavior with all routers, but from my own experience I was not able to open the Admin UI within a web browser until I changed my ASUS router’s subnet to 192.168.1.x. The Admin UI is useful for viewing the signal strength on your upstream and downstream bonded channels, among other things (such as the connection status, etc.).A number of reviewers have written negative reviews of this modem, mainly complaining about downstream issues. Make sure your downstream QAM signal Power Level is between -15dBmV to +15dBmV on all channels, SNR should be 35dB-45dB (ideally). If you notice that your power levels are outside that range, you will likely have downstream connection issues and not have full throughput. Upstream Pwr levels should be between 35-55dBmV. If your numbers are outside this range, call up your cable provider and request they send a technician to check your signal levels and correct them.This modem will connect to up to 32 QAM channels on Docsis 3.0 and easily reach throughput speeds of up to 1Gbps and beyond on Docsis 3.1. For those who are wondering if the MB8600 works with Spectrum, it definitely does.
Customer –
Easy to set up and save $11/mo to Comcast.
Trevor –
The model I acquired would not connect to my ISP at all.
Doug –
It is fast and beautiful. What else could you want? Two ports for two routers.
Customer –
Works great!
Steve K. Scherr –
So far so good – I just called my internet provider before swapping this out from my old now “unsupported” modeland they changed the info for the device.Once they were done I hooked it up and they got a connect then I plugged it into my router and everything came right up..Easy Peasy
Mark Twain –
It gets the job done at 1Gbps. Connect this to a Ubiquiti Networks Security Gateway and some Ubiquiti wireless APs and POE switches, and all your networking problems will be gone for good.
Grandpa –
Easy to install, works perfectly
BB –
Expensive and slow to boot, but it does work with comcast and gets over 900Mbps down.
Peter C. Duthie –
Seems to be working well. Bought it when I upgraded to gigabit service from Comcast. The X6 box from Comcast was OK, but I like to have more control on my network and with this modem I can monitor signal levels on all the up and down channels.
Customer –
This modem is really fast and great price, fast shipping
jake –
Item worked excellent.
John Smith –
I did not buy this from Amazon, but also have connection issues like all the other negative reviews. It took over an hour for the modem to work for me after my ISP confirmed everything was good and the signal was strong. Connection lost when I hooked up the router, that took two hours. Since set up, I have lost signal four times in less than a week. When the modem is working, it is awesome, but the dropped signals are not worth the hassle.
Francine G. –
Easy setup and works like a charm!
Nicholeknc –
A must have upgrade over the SB6121. Easy to install. You will have to call Xfinity to get it activated to your account. You will need Serial number, model number, and MAC address. Be prepared to explain you are upgrading!
Christian –
Not compatible with TWC / Spectrum. I was told it was by several TWC representatives that it was compatible.
Kyle C-Bman –
So far no issues. Does get the best speed, but can’t tell it it’s the modem or our provider.Extremely easy to set up (took maybe 10 minutes) and have had no issues. Would recommend!
Jeremy S –
Been using surfboard modems for about 10 years now. This thing is awesome. I pay for 200mb down service. My old surfboard only got me about 160mb. I plugged in this new one and immediately I’m getting about 240mb on all my lan systems. Love this thing.
Customer –
Very bad. Stopped working after 2 months. Not sure what to do now.
Jon P. –
Watch out, they are shipping a ONE-port version of this with the same make/model.Perhaps it is a cheaper, dumbed-down version of the the product, perhaps the 4 ports that made it more future-proof where causing confusion, but either way, this looks just like a traditional one.Got to wonder what they changed inside…Hope this helps someone.
Murph –
Works as expected, replaced a netgear DOCSIS 3.0 I had but updated service and needed the new speeds and bonding. Lights tell you that you are using DOCSIS 3.1 or DOCSIS 3.0 so that is helpful to see. Has been stable since its been running and its been a few months so I am happy
Kasem O –
Works great, looks great. Get reliable 900mbps+ speeds no prob.
Ravi Kumar V –
No difference in speed..as usual crappy buffering. Looks like its not modem issue its the providecto upgrade lol
Neiser –
Great product, item as described, fast shipping, will do business again.
Foxxwoof –
I initially bought this modem to have some level of future proofing. It turned out to be a mistake. I am using it on Comcast/Xfinity cable, with a 150Mbit down and 50Mbit up connection. I managed to keep it for about 8 months (7 months too long)…It would either get massive slow down or completely freeze up about 4-5 times a day necessitating power cycling the modem. Invariably this reboot would restore the really fast speeds this modem was capable of for about an hour. I called Comcast out probably a half dozen times during that time period to investigate the drop offs. I was getting a lot of T3/T4 critical time out errors, high upload power levels (above 50dbm) and marginal SNR values. Comcast never found a problem with their lines or distributions, and even installed a new drop “just to see” if it would fix it. The final nail was after the new drop the tech was still seeing that the power levels the Motorola modem was reporting were extremely high. They hooked up one of their “rental” modems and the power levels dropped to normal levels.So out with the “new” Motorola and in with the Comcast rental. At least for now. In the trash the Motorola goes.
J. Frauenheim –
This high end modem is really not needed unless you are going for a faster connection – 450mb/sec for comcast or 1 gig. For lower end, the 32 channels help to make the performance more stable. Cable speed though is just as dependent on the connections of existing cables as well as the modem.
Monkey Rat –
The Xfiniity compatible Modem was super easy to set-up following the Quick Start guide included in the box. Word of advice for Comcast / Xfinity subscribers — when stepping through the set-up Wizard, selecting the option to text an activation code is a joke — the code is only good for 15 minutes but I didn’t receive the text until 30 minutes had passed; just stick with your Xfinity account name for the activation and provisioning.Xfinity upgraded to DOCSIS 3.1, and, while my own 6 year old trusty Motorola Surfboard SB6580 was working fine, Xfinity found every reason to pester me about an upgrade and how much I’m missing not having a 3.1 modem lease an upgrade. I prefer to own my own modem, so, after perusing compatible modems for my region on Xfinity’s approved device page, I narrowed my choices to the ARRIS Surfboard SB8200, Netgear CM1000, and, this, the Motorola MB8600. All three are comparable at 1001 Mbps, 32 down x 8 up DOCSIS channels, and DOCSIS 3.1.All the cool kids love the Arris — especially after they ditched the very problematic Intel PUMA chipset and went with the Broadcom’s offering — and for very good reasons, it has great hardware specs. Sporting 3GB of RAM, 128MB /16 of NAND flash memory it’s a tasty treat. And, were it not a horrific white box that clashes with everything in my apartment, I’d happily have purchased it.Vanity, thy name be Monkey Rat, I know.I’ve never had a lot of love for Netgear, and, I found its hardware lacking — 128 MB of flash memory and 256 MB of RAM. Ultimately not a huge game changer, with current theoretical home speeds at 1Gb, but one would expect something a tad more, well, more from a name like Netgear. While its feature rich — which, is saying something for a cable modem — I really saw no reason to down this path.That clashing white Arris was looking tastier at this point.Then I compared the MB8600 to both and found a happy place. 512 MB of RAM and 128 MB of NAN — a buck cheaper than the Netgear with a doubling of the RAM, and while not as expensive — marginally — than the Arris, and certainly lacking a bit in the hardware department, but I paid more for future ability to bond upwards of 4 separate lines. However, the LACP technology requires a higher end router, and faster than a gig speed isn’t necessarily right around the corner, but, this device positioned nicely for a future with a potential of 4Gb.Word of caution — it’s a BIG device. If you’re familiar with the older Surfboards, this is easily double the size in height and does not come with any sort of mounting option. However, it has great ventilation thanks to a well aired grid pattern on the side.So, how does it work? My internet plan is the BLAST! 150 Mbps (stop laughing) — and i assure you, I’ve never seen that even in the dead of night — wired speeds show an increase on speedtest.net but it’s not really all that noticeable, whether plugged in directly to the cable modem or my ASUS RT-AC86U router, notebook and desktop performance were negligible. However, wireless performance for my nVidia SHIELD K1 tablet and Google Pixel 2 phone were significantly improved – I found this a little odd as they’re still going through a router, but, I can’t argue with results.I keep forgetting the MB8600 has a baked in spectrum analyzer utility I need to check out — I’ll add an update when I do.Ultimately, I like it — I play Everquest (the original) and noted better response times, but again, the MS aren’t earth shaking or setting the sky afire. Stream the occasional movie, and really I don’t have any complaints, and can only praise the device for its eye-popping Wi-Fi boost, for which I have no good explanation.I may change out my Cat5e for Cat6 and upgrade my router next — hopefully wringing a couple more Mbps out. But, really, I think it’s time to call xfinity and have to do some line tests. I will provide updates on that as well.
Jace & Angie Erickson –
Had constant problems with losing connections to the internet. Ended up buying a Netgear after six months. This is not worth buying!
Wayne J –
Seller delivered as promised. Product is excellent
Jen and Rick –
easy install and this thing is fast
Customer –
the modem is awesome I am running two Xbox ones 3 4K uultra televisions and four computers through this modem and it provides the full bandwidth for all of these devices and never misses a beat.
Clint Hall –
I previously purchased the Arris Surfboard SB8200 modem. It rebooted several times a day and was hot to the touch. I did read that the Arris SB8200 did have issues with running hot and rebooting several times and also required a hard reset. I processed an exchange through Amazon, and the second modem did the EXACT SAME THING. I also ensured that I have a good strong signal from Comcast. Their tech came out and replaced the splitter with one which is also a power booster. This was all done while I had the second SB8200. This did not fix the issue with the SB8200. Therefore I got this Motorola MC8600. Setup was a breeze, and I was able to quickly set it through comcast’s website without any issues. There have been NO restarts or reboots with this mode, and the device is cool to the touch meaning there are no overheating issues. All is well now!
Paul K. –
I purchased this modem after my ISP increased my internet speed and my previous modem (SB6141) wasn’t able to achieve that speed. I wanted a modem with DOCSIS 3.1 support so that it would still be good enough in the event my ISP improves its speeds further over the next several years, as well as something that was likely to have low heat output as there would be potentially less risk of running into hardware problems over time. I picked this one for a few reasons, primarily based on the other reviews here. This modem had several other reviews from people who said the modem felt cool to them compared to other models. I had tested and reviewed a previous Motorola model (MB7420) in 2016 and thought the heat output was reasonable there despite being higher than the SB6141 but ultimately returned that modem and decided to keep using my SB6141 until I actually had a better reason to upgrade. One of my other wish-list items was low power consumption, because I keep my modem and router plugged into a UPS battery backup and so the less power used the longer my internet access can remain working during a power outage.I set up and activated the modem then connected it to my router. The modem was connected to my ISP in DOCSIS 3.1 mode with 29 out of the 32 downstream channels bonded plus 4 out of 8 upstream channels bonded, in case that makes any difference. I have an internet telephone adapter connected to the router, as well as a tablet so there is always some light network traffic from those devices to maintain their connections even when I’m not home. To provide sufficient time to get a typical temperature reading in this state I waited until I got home from work the next day, so that the device had been running for over 20 hours at that point. I used the thermal camera to measure the device surface temperature and capture the photo attached to this review. Ambient room temperature was 75 degrees Fahrenheit at the time according to the wall thermostat. At the hottest point on the outside of the modem the temperature was reading 99 degrees F. This was the highest reading I captured, the reading fluctuated between 97F and 99F. (37 degrees Celsius) This is a very good reading and I wasn’t expecting it to be so low because when I measured the MB7420 in 2016 I was getting 111F. (You can look for my review of that model for the corresponding photo.) It is clear that Motorola managed to improve the efficiency of the modem with this new model. For comparison, I was getting roughly the same temperatures from my SB6141 which was also a good modem.Next I measured power consumption from the modem in the same state described above. Power consumption was measured using a Kill-A-Watt P3 device. Power use in this state measured at 6.6 watts. For comparison the older MB7420 model measured at 7.7 watts in the same situation, so once again further improvement here compared to their previous model even with being capable of twice the speeds of that modem.From a performance and efficiency standpoint, the MB8600 is a great modem and I will be keeping this one. I’m now getting speeds 10% faster than what my ISP promises again, but in my experience that was the case for lower speed tiers with my previous modem as well.At the moment I have no complaints about this modem. I would recommend it.
eastbayddt –
Faster apps for the cable.
Paul K. –
I purchased this modem after my ISP increased my internet speed and my previous modem (SB6141) wasn’t able to achieve that speed. I wanted a modem with DOCSIS 3.1 support so that it would still be good enough in the event my ISP improves its speeds further over the next several years, as well as something that was likely to have low heat output as there would be potentially less risk of running into hardware problems over time. I picked this one for a few reasons, primarily based on the other reviews here. This modem had several other reviews from people who said the modem felt cool to them compared to other models. I had tested and reviewed a previous Motorola model (MB7420) in 2016 and thought the heat output was reasonable there despite being higher than the SB6141 but ultimately returned that modem and decided to keep using my SB6141 until I actually had a better reason to upgrade. One of my other wish-list items was low power consumption, because I keep my modem and router plugged into a UPS battery backup and so the less power used the longer my internet access can remain working during a power outage.I set up and activated the modem then connected it to my router. The modem was connected to my ISP in DOCSIS 3.1 mode with 29 out of the 32 downstream channels bonded plus 4 out of 8 upstream channels bonded, in case that makes any difference. I have an internet telephone adapter connected to the router, as well as a tablet so there is always some light network traffic from those devices to maintain their connections even when I’m not home. To provide sufficient time to get a typical temperature reading in this state I waited until I got home from work the next day, so that the device had been running for over 20 hours at that point. I used the thermal camera to measure the device surface temperature and capture the photo attached to this review. Ambient room temperature was 75 degrees Fahrenheit at the time according to the wall thermostat. At the hottest point on the outside of the modem the temperature was reading 99 degrees F. This was the highest reading I captured, the reading fluctuated between 97F and 99F. (37 degrees Celsius) This is a very good reading and I wasn’t expecting it to be so low because when I measured the MB7420 in 2016 I was getting 111F. (You can look for my review of that model for the corresponding photo.) It is clear that Motorola managed to improve the efficiency of the modem with this new model. For comparison, I was getting roughly the same temperatures from my SB6141 which was also a good modem.Next I measured power consumption from the modem in the same state described above. Power consumption was measured using a Kill-A-Watt P3 device. Power use in this state measured at 6.6 watts. For comparison the older MB7420 model measured at 7.7 watts in the same situation, so once again further improvement here compared to their previous model even with being capable of twice the speeds of that modem.From a performance and efficiency standpoint, the MB8600 is a great modem and I will be keeping this one. I’m now getting speeds 10% faster than what my ISP promises again, but in my experience that was the case for lower speed tiers with my previous modem as well.At the moment I have no complaints about this modem. I would recommend it.
S. Taylor –
Skip the $5 a month modem rental charge from Xfinity. Buy this and own it. The Xfinity tech activated my account and installed the router for me. It took about 20 minutes with troubleshooting but after it’s up you won’t have any problems. It delivers the promised speeds. Plus you save $60/year. Three months on and no issues.
Shertex –
This modem works with xfinity and way to set-up. That said I did not realize at the time of purchase that it is cable modem only with No/No wi-fi connection. So I had to return it as I really needed a wi-fi router. Returned through Amazon which was painless as usual.
M. Kelly –
Setting this up did require a call to my ISP, but was fairly straightforward. Subsequent speed test was highest I’ve seen since moving here. Time will tell how stable the connection is…it’s been online for about three hours now.
Customer –
Got this modem because Comcast said they no longer support my old modem, imagine that, but anyway glad I did! Easy to setup, web pages load so much faster on all of our devices. Great product.
Rich W –
Purchased this Gigabit modem along with a Motorola MR2600 Gigabit router to replace my TP-Link modem and router. After only 3 days I reinstalled my TP-Link equipment. The Motorola equipment worked, but I was disappointed with the performance.
David Wright –
This reciew is of the modem only model. Install was simple connected coax, connected power, connected ethernet and powered on. Nodem negotiated to DOCIS 3.1 no problems. 5 star for HW below is my comcast experience completely unrelTed to the quality of this product.The Comcast Xfinity instructions were right but, in my case I was replacing an existing modem and they did not work. Had to call Comcast to get MAC binding issue resolved. After about an hour they had it paetially working, I could get on the internet but only comcast and other addiliated companiez websites were working. There was definately an issue with the Comcast IPv6 DNS servers I received via DHCP. As a result I spent another 1.5hrs with Comcast support and they had to call the next day supposedly. I never received a call called them around noon and another hour on the phone with them and internet was now working properly. Comcast customer support is awful especially because they are a monopoly in my community. I f I had any other decent option for internet I would have fired them over this experience.
A. Olmos –
I’m sorry others have had issues with this modem. Some of the bad reviews made me nervous about buying it.I purchased mine in April 2018 and it has been working perfectly with Xfinity Oakland, CA.I have a friend who bought one as well and he had the same results in a different city.As can be seen in the picture I included, I’m getting 941 / 41.8 Mb to my desktop using this modem.My setup is:MOTOROLA MB6800 -> Netgear Nighthawk X4S R7800 -> Netgear gs750e -> desktopYou may want to consider the MB6800 cable modem and the Netgear R7800 wireless router rather than the all in one Netgear C7800 wireless cable modem router.This way when 802.11ax comes out in 2019, you can just upgrade the wireless router and save some money.(I’ve gotten 510 / 41.4 Mb to my iPhone via the Netgear R7800, it’s fast, and the range is one of the best you can get.)What about getting >1Gbps via Link Aggregation?Yes, this modem has 3 hidden ports under a removable sticker.I removed the sticker to test them to be sure they worked.The extra ports mean I could in theory set up two Cat 6 ethernet cables from the modem in parallel to my switch and two Cat 6 cables to my desktop.MB6800 => Netgear gs750e => desktopIf >1G Internet became available from Xfinity, I could exceed the 1Gbps limit of a single Ethernet.I tried this setup and was not able to get it to work. It is possible I configured something wrong,but…I was able to get:MB6800 => Desktopto work with Link Aggregation. I don’t really want that setup since the Desktop machine wouldneed to act as a router and rebooting it would take down my network. But, the desktop was ableto DHCP an IP from the MB6800.There isn’t a whole of of configuration for the MB6800.You either set it in single link mode (default) or link aggregation mode, and that’s about it.The rest is controlled by the custom firmware it loads from your cable company when booting.The modem has worked well. I haven’t had to reboot it, or had any issues with it.You don’t really know it’s there as your administrative tasks will be with your router, not the modem itself.I’m happy with my purchase. I hope Xfinity rolls out higher speeds so I can test them out.
C. B. –
Great modem. I was debating between Arris SB8200, Netgear CM1000 and this Motorola MB8600. I’ve ended up buying the Motorola and I couldn’t be happier. It runs cool and blazing fast. I’m in Phoenix, AZ using this modem with Cox Communication on DOCSIS 3.1. The installation was super easy, I was up and running in less than 10 min. I’m getting 944 Mbps Download and 36 Mbps upload. Very happy with this purchase.
Robert B –
The modem works and it saves me the $13 a month Comcast wanted to charge me to continue renting their Arris XB6-A DOCSIS 3.1 gateway but I expected better performance.The XB6-A has an Intel Puma 7 chip and is supposed to be inferior to the Broadcom chip in this modem but looking at my modem stats, you would expect this thing to fly and unfortunately it doesn’t. Where the XB6 pretty consistently downloaded between 900 and 940Mbps, the MB8600 runs between 825 and 900Mbps and the upload on the XB6 was a solid 41Mbps, it fluctuates between 22 and 40 on the MB8600.With that said, we don’t really do anything that maxes out the connection so the drop doesn’t really impact things that much but I expected more for the price and I’ve factory reset it twice and my levels are fantastic (just look at the crazy low codeword errors, I don’t think I’ve ever seen a modem have so few).
Sargento –
If you are looking to purchase your own modem DOCSIS 3.1 compatible with Comcast Xfinity, this is the one. Is super easy to setup, and the performance is EXCELLENT with awesome warranty and Tech Support for two years. I paired it with a TP-Link AC2300 MU-MIMO Router that makes an excellent combination for my network. If are considering on stop paying for Modem/Router rental fee and you want Gigabit speed internet I highly recommend this choice. There is only two Modem out there comparable with Gigabit Speed DOCSIS 3.1 fromm Comcast Xfinity. The Netgear CM1000 and Motorola MB8600 DOCSIS 3.1. Don’t be fool by all the specs the other competitor offers, they blown way out of proportion to deliver the same speed. The bottom line Motorola has an Excellent reputation with their devices and the MB8600 delivers that. Also, word of advise don’t buy the modem use, buy it from a reputable dealer and safeguard your receipt inorder for Motorola to honor the 2 year warranty. The Netgear only offers 1 year and 3 months of Tech Support.
walter g prill –
This modem works better than expected on cox. 300Mbs plan. I replaced an Arris 6141 and was getting 265 down and 30 ish up. With the Motorola see attached during the middle of the day, see attached pic. I’m content.Walt Prill
Customer –
Cable provider in our area recently offered 1GB internet and the previous surfboard wasn’t compatible. Upgraded to the MB8600 which is approved for use and got an extra ten to twenty MB data transfer rate out of the box. Speed is dependent on time of day but that’s expected with cable, and considering the price was about the same for “boost” we now enjoy the additional bandwidth for even more. web surfing, streaming, Wi-Fi and IoT (Alexa, nest, etc.,) devices. House is hardwired as well as Wi-Fi and additional bandwidth was measured at the tap where IPV6 was the fastest and IPV4 throughout the remainder of the home network. Its worth noting that running a 16port GB switch behind the modem there was minimal noticed decrease in responsiveness. For the extra $$ this modem improved our performance. Remember to CHANGE the default PASSWORD on the modem after installing, as this unit is internet facing and comes with default password written on the box.
Scotterz –
I upgraded to Cox Gigablast internet service, the speeds are amazing and I haven’t lost connection once since I upgraded. Definitely worth the money.
Customer –
Cut the cable recently and installed 5 Roku’s at home. My old 100 Mbs internet was getting the herky jerky’s when everyone was online. Upped my Internet connection to 400 Mbs and found my old modem was obsolete so Rather than rent a modem for 10 bucks a month. I did the research and found the the new standard for modem protocol is 3.1. The Motorola MB8600 replaced my SB6121 and speeds went up over 4x even the Spectrum tech was impressed.
Chris McB –
Worked ok for the last year. Had some issues over time with lots of corrected & uncorrected errors, but comcast always blamed the modem.In the last week I’ve been dropping my internet connection every day a few times each day. Today I logged into the modem to see what’s happening after a reboot (I was actually convinced it was my router for the last few days so I ignored the modem). I have a screenshot of my current status page, but in under 90 seconds, one channel racked up 130,000 corrected errors…I would tell everyone to stay away.
Rob –
I upgraded my Xfinity internet speed to 1000mbps (gigabit) and my router could handle the speed, but not my modem. So I picked up the Motorola MB8600 and it’s been working great! When my desktop computer is wired in I’m getting up to 1300 mbps download and 42mbps upload. Wifi download speed on my iPhone X is about 414 mbps and 41 mbps upload.Setting up was simple. I turned my router off, plugged the new modem in, reset my router, turned my router and modem on and then went to xfinity.com/activate and that was it. I have nothing bad to say about this modem, very pleased with it.
Ben –
The MB8600 meets all of my expectations for a cable modem. I had purchased a competing modem from another company which failed on me within two weeks. The MB8600 was that modem’s replacement and it has worked flawlessly since I purchased it.Pros:+ Solid connection, no internet or signal issues at all+ Receiving speeds of ~350/30 Mbps on a 300/30 plan+ Fully compatible with most 1 Gbps cable internet plans+ Fully featured web interface (access via 192.168.100.1), detailed cable signal information available+ Runs cool, a similar modem from another company ran very hot+ Easy setup, nothing needed beyond activating the modem with your ISP (all modems need this)Cons:- Relatively large footprint for a cable modem, it may not fit easily in tight spaces (e.g. small network cabinets like mine)Considerations:• While you can hook up this modem directly to a PC, I would highly recommend getting an external router instead
Tim –
Good speeds. Topping 300mbps. That is tops for my service. Sure it can do more. No problems so far at all. Only with service provider. All fixed now.
Ken Bunch –
Setup for my new Motorola High Speed Modem has made my Internet Service 7 times faster and very stable.Motorola is known for high quality and engineering.Thanks for the easy plug and play equipment.Faster and reliable with Motorola!
Gerald Pottier –
This is a fast modem. I was going to go with a model that was both wifi and modem, but after reading reviews on both of the major two (Surfboard, and Netgear) I decided to go with good ol’ Motorola combo set. Also bought the MOTOROLA AC2600 to go with it along with 4 of the TP-Link Powerline Adapter AV2000 and I am pleased. The entire house enjoys fast internet speeds.
user –
I am an Xfinity/Comcast customer. Set up was super easy. Over in minutes.Using it with comcast Gigabit Internet, download speed is around 945Mbps +/- 10-15mbps, upload speed is around 40Mbps +/- 2-3Mpbs. The modem is paired with Netgear Nighthawk X10 router with DD-WRT firmware. Using this setup over 11 months, i dont really have any issue with it.
Randy Cross –
The MB8600 is the best docsis 3.1 modem you can get currently. With the correct “LAGG/LACP” setup, hardware configuration this modem is able to max out my gig service with Spectrum. Provisioning at this tier is 1220mbps down and 42mbps up and its able to saturate the connection when using LACP, multi gig router and client . I would say anyone having issues using this modem are running into something unrelated to it. The modem has 100% stable and reliable for me, even if you don’t want or can use the LACP option of the MB8600 it would provide maximum throughput at any speed tier.
Motown Doc –
Purchased as an upgrade to Motorola SB6121 and it’s not living up to expectations. It constantly slows down and disconnects. Never had similar issues with the SB6121. Not recommended.
Bohdan –
I bought this modem because it has 4 Ethernet ports (they are hidden behind the sticker and only 1 is visible), so I can connect all my devices there without an additional switch. Also with there 4 ports it theoretically provides up to 6 Gbps speed with Link Aggregation Group, so it is the best modem right now if you don’t want to change a modem once providers allow more than 1 Gbps speed.Unfortunately, it is only possible to connect your other devices to more than one Ethernet port if your provider gives you more than one IP address (Xfinity does not), so I couldn’t use that for this case and I still have to use a separate switch. Also, I had a problem during installation, but it is more like Xfinity problem, but still related to this modem, since it does not offer LAN, but instead gives you external IP address directly. I connected first to my laptop to test actual speed and then I switched cable to the WiFi router and the internet was not working. It appeared that Xfinity remembered the MAC address of my laptop and refused to connect the router. I had to restart the modem to fix it.The connection speed is really great. I was able to get 1010 Mbps, which is almost 1 Gpbs, which is maximum for my provider. I do recommend this router if you want to get max speed from your provider.
David Hall –
Considering the cable company usually charges $10+ a month for their modem, I figured after a bit over a year this modem will have paid for itself. Now it has been over 2 years and I am using it with a different cable company. I have used it with both Cox and Xfinity and each time it was as simple as calling and reading off the numbers to them. I’ve been running 1Gbps internet and this modem has room to grow if they ever expand in the area. Certainly has paid for itself.
Andrew Grochowsky –
easy to install works great with Media Com Internet for the ISP Along with a ASUS Rog Rapture ax11000 WiFi 6 router.
Vincent C. –
Happy that I was able to connect at the 1gig speed that was paid for, even though my modem was not on the Optimum Online/Altice certified device list. After doing much research I took a chance to purchase this modem. As an IT specialist, I purchased 3 different modems at the same time and decided 1 out of 3 is going to work and I can return the other two. I opened this Motorola first being that this is the one I really want to keep and was determined and hopeful that this modem can be provisioned and run at the service I paid for. After one additional call to Optimum, the Tech and I were able to have this up and running at full speed in less than 10min. I Never had to open the Netgear or the Arris and just returned them the next day.So for the record anyone looking into 1Gb service with Altice/Optimum you will be happy to know that this modem works like a charm. Yes, you will be told that it’s not a supported device (all that means you will have to do your own support/troubleshooting) being that it’s not on their approved device list, but being that it’s DOCSIS 3.1 you should have no problem just have them reboot your device after the first hour of service and be sure to use CAT7 and you should be fine. (See attached photos)
Bruce –
This was an upgrade for my old cable modem. My old modem was no longer supported and kept dropping connection. I am now getting a rock solid connection and 100Mbps faster download rates. Speed test was giving me about 138Mbps, and as you can see in the screen shot, I’m getting 239Mbps now! Should have switched over to a newer modem a long time ago.
milesvinson –
Bought to install at my mom’s house on Comcast Xfinity after the Arris SB8200 died after 34 months of continuous use. The MB8600 doesn’t have wall mount slots so I made a bracket from a piece of 3/4″ aluminum so that it could be wall mounted. As you can see in the pictures of it mounted next to tp-Link TC7650 it is close to the same size.I first installed and activated it on Suddenlink at my home to see if it would work. I have gigabit/50 service and after calling Suddenlink tech support, giving the MAC address and a few reboots, it was up and running fine. The only strange thing was that after Suddenlink provision, I could no longer access the modem webpage at 192.168.100.1 like you normally can.Took it to mom’s house and mounted it. Activated using the self provision portal on Comcast Xfinity without any issues. On Comcast Xfinity access I was able to access the modem webpage at 192.168.100.1 like you normally can. 33 downstream channels(32 QAM + 1 OFDM)/5 channels upstream. Full speeds+ with Blast! internet.