Customer Ratings & Reviews

Purchased this Modem new on 1-24-2022 so its beyond the 15 days return. It is nothing more than problematic. Constantly falls offline. Had a Motorola DOCSIS 3.0 for 5 years with no trouble. This MB8611 I've had Comcast out 3 times replacing components like the underground service cable, various connectors and splitters. Been in touch with Motorola and they keep pointing to the ISP. Comcast says all the signal levels are correct but the Modem still fails several times a day. I am back to my old DOCSIS 3.0 MB7420 modem. I suspect this new modem will meet the sledge hammer fate, lost $179.99 on this.

So the modem was good while it lasted. I had this thing a little less than 3 months before it completely fried. No really reason it should have it just fried. As is typical in these situations it was just outside the time I could have taken it back. To give you an idea exactly what I mean in terms of how long it lasted, I purchased 11/6/2021 and it died on me 01/21/22. So not long at all. :(

Just search for "MB8611 Reboots" and you'll see the problem. I don't know if I got a bad unit or if there are conditions under which this unit will have problems that only some will face, but my experience has been a nightmare. Mostly my internet worked fine (comcast) but about 3 times a day, the internet would just stop working for 1 minute. Most of the time it would go unnoticed, but if I was in the middle of a game, or on a zoom meeting, or watching a video, it was extremely disruptive. This is a new house and I was beginning to think I just had a bad connection in the area and would be stuck with this situation. Looking at my router logs, I could see that my WAN connection was randomly going dead. I researched and figured out how to log into the modem and found that the entire thing was rebooting during these episodes. Meanwhile, even while diagnosing the issue, this modem actually started failing more often just because I was logged in and looking at the logs. After some digging, I found posts from other people having a similar issue. The only solution anyone gave was to try a new modem. I bought an Arris S33 from best buy and haven't had a problem since. This problem persisted for me long enough that I can't return the MB8611, so now I'm out $200 bucks and am left with a useless piece of plastic. Save yourself the headache and don't play RU roulette with this thing. I'll never buy another Motorola product.

Trouble with router not handling Comcast hi speed internet. Comcast and Geek Squad techs agreed that new router is needed to place this one.

Comcast said the unit I purchased was previously activated. They wanted me to contact Best buy to find previous owner to release Mac. Needless to say, I returned it.

Bought this to replace a Comcast modem. Modem intermittently drops the internet connection for a few minutes at a time. The event log shows T3 timeout errors. Motorola claims that the modem is within specs and that Comcast must have intermittent noise on the line. Comcast tech checked the line and said the signal is good. Might have to replace it just to get a more reliable connection.

This modem worked for only 5 months and then started dropping connection and rebooting all day long. My internet provider confirmed it was a signal issue. This seems common in other reviews. I'm out of the return window to Best Buy so trying to replace under warranty. It has a two year warranty so we'll see but I don't have confidence that the replacement will last.

Do not buy this modem if you use Xfinity. Constant resets at least once per day at random times.

Random keep restarting couple times per day! Motorola please improve your products quality!!!

Had two of these. When they worked, they were great. But, they would just drop connection for a few minutes after an hour or two. That may be okay for casual users, but when you need it for work to talk to customers that isn't acceptable.

The description of this product was not clear and we had to return it because it was not what we thought it would be.

not a great router but you get what you pay for speeds weren't as fast as hoped

I bought this to "upgrade" from my old Netgear modem so I could use a faster connection speed. Sadly this modem has had frequent T3 timeouts that crash my internet connection. Comcast came to my house twice but could not fix the problem and finally blamed my modem. I've now switched back to my old slower, but much more stable Netgear modem.

Drops offline 5 - 10 times per day. Very annoying.

This modem was cutting me off every day or two for the first 2-3 weeks, but the last week, it has been doing okay. I was about to see if Best Buy or Motorola would replace it with another one, but it seems like it got over the problem it had, but I will still rate it a 2 out of 5 until it proves me wrong.

Oh Motorola, what have you done with yourself!? Failed after 6 Months! Shortest lifespan ever of a Cable Modem. Simply wouldn't connect to Xfinity/Comcast anymore. Installed a new Netgear and I was back online.

Bought to replace xfinity modem . This item does NOT have WIFI . Had to return item

Event log interface not as good as others. Excessive overheating, many drops/disconnects.

Great product, but I needed a router too. Needed Gateway, not just modem.

I have Comcast GIgabit service. I had a Netgear modem which gave me speeds around 950. When that broke I bought this one. Since activation the down link arrow constantly flashes. I was not get speeds between 12 and 100. Numerous calls to Comcast with no luck. The last rep told me my modem is fine and it doesn’t support gigabit. At this point I give up because nobody has a clue. Motorola blames comcast and comcast blames the modem.