Motorola MB8600 Review: The Go-to Gigabit DOCSIS 3.1 Cable Modem

The Motorola MB8600 is an easy choice. At some $150, it makes a gratifying upgrade for those moving from a sub-Gigabit to a Gigabit cable broadband plan.

If you’re in that situation, go for it, you won’t regret it.

Dong’s note: I tested the Motorola SM8600 with Comcast. While the modem will work with other cable providers, the experience expressed here is that of Xfinity subscribers.

Motorola MB8600: A frill-free DOCSIS 3.1 modem

Out of the box, the MB8600 looks like a typical cable modem. It’s a rectangle box standing on one of its sides. You’ll find the power port, the coax service port, and one Gigabit network port on the front back.

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Supposedly, you can remove the yellow tape to get access to the modem’s three extra LAN ports. These ports serve the situation where you have multiple static IP addresses.

You can also use the 1st and 2nd ports to form a WAN Link-Aggregation connection. Since my Internet plan is a sub-Gigabit residential one, I decided not to try any of these extra ports.

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The way cable modems go, the network port decides the top broadband speed this modem caps at 1Gbps. On the inside, though, the Motorola MB8600 features DOCSIS 3.1, capable of getting up to 6Gbps of Internet bandwidth from the provider. It can also work as a 32×8 DOCSIS 3.0 modem.

On the front, the modem has a vertical array of LED status lights. These are helpful during the setup process or when you need to check on your broadband connection status.

Most of the time, though, these little blue and green lights are a bit too bright. If your Internet drop is in your bedroom, it’s a good idea to cover them with a piece of tape.

Simple setup process

I tried the Motorola MB8600 (via a few units) with a couple of Comcast Xfinity accounts, and the setup process was straightforward. You can find detail in this post, but here is the simple breakdown:

1. Connect the modem securely to the service cable.
2. Turn it on and wait for the signal light (2nd from bottom) to turn on solid green.
3. Connect a computer to the modem’s LAN to a computer. Alternatively, you can also connect this port to a WAN port of a router, then connect the computer to the router (either via Wi-Fi or a network cable.)

And you’re done with the hardware setup. Now it’s time to activate the modem. For this, you can just call the provider and give them its MAC address, located on its underside.

Or, you can do that yourself, which I did. When I launched a web browser on the said computer with an Xfinity account, I got directed to the activation page, where I entered my account information. And voila! Mission accomplished.

(By the way, it’s always a good idea to restart the router after the modem has been activated.)

Most other cable Internet providers should have a similar self-activation process. But, again, when in doubt, it never hurts to give yours a call.

While generally, there are no user-accessible settings in cable modems, the SM8600 does have a web interface reachable via its default IP address, which is 192.168.100.1. The interface shows its status, logs, and other useful information about the WAN connection.

Motorola SM8600: Hardware specifications

Name	Motorola MB8600 DOCSIS 3.1 Cable modem
Model	MB8600
Standard	DOCSIS 3.1, DOCSIS 3.0 32×8
Top WAN speed	6Gbps
Ports	1x 1Gbps LAN, 1x Coax
Top Internet plan supported	1Gbps
WAN Link Aggregation	Yes
ISP supported	Comcast Xfinity, Cox, others
Dimensions	7.25 x 2.25 x 7.88 inches
Weight	1.15 lbs

Excellent download speeds and reliability

For this review, I tested the Motorola MB8600 (via a few units) with a couple of different Xfinity accounts collectively for a couple of months.

The modem proved to be fast and reliable. There was no disconnection or any other issues.

In the San Francisco Bay Area, the modem consistently delivers speeds faster than the plan for those with a sub-Gigabit connection. (Mostly likely because Comcast tends to provision the connection higher than the paid speed.)

Specifically, for an account with a 400Mbps download speed, I experienced up to 460Mbps. And with a 600Mbps plan, I was able to get faster than 700Mbps. The upload speed was never faster than some 20Mbps, which is normal for all cable connections.

On the other hand, when tested with a Gigabit cable plan, the modem capped at around 960Mbps. That was likely because a Gigabit connection generally caps at around 950Mbps after overhead.

Needless to say, your mileage will vary. Cable broadband connections tend to vary from one area to another. But it’s safe to say the Motorola MB8600 sure can deliver Gigabit-class broadband.

Conclusion

If you have a cable plan of (close to) Gigabit, the Motorola MB8600 DOCSIS 3.1 Cable Modem is a safe bet.

Get it and a decent router, and rest assured you’re getting the most out of your Internet connection without having to pay that pesky monthly rental fee.