# Recommend a cable modem **URL:** \ **Category:** In My Humble Opinion\ **Created:** [December 30, 2012, 12:19am UTC](https://boards.straightdope.com/t/recommend-a-cable-modem/645531 "2012-12-30T00:19:09Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [December 30, 2012, 12:19am UTC](https://boards.straightdope.com/t/recommend-a-cable-modem/645531/1 "2012-12-30T00:19:09Z")
One of those things I never think about is that I’ve been paying $7/month for a cable modem for the last five years. Stupid, eh? So I think I’ll stop renting one from Comcast and buy my own. Knowing nothing, I’ve read a couple of negative reviews on Amazon for the Motorola SB6121 and SB6120. One review for the former says that the SB6121 has issues working with Comcast cable service, and that the SB 6120 worked better. One review for the latter said that the SB6120 didn’t play well with Comcast’s service. (Note: I like to read the negative reviews to see what problems people face.) Should I consider buying one of these modems? Or is there another one that I should consider? ---
**Author:** ![ZipperJJ](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zipperjj/32/211_2.png) [@ZipperJJ](https://boards.straightdope.com/u/ZipperJJ)\ **Post date:** [December 30, 2012, 12:24am UTC](https://boards.straightdope.com/t/recommend-a-cable-modem/645531/2 "2012-12-30T00:24:58Z")
Did you start here? [List of approved modems for Comcast.](http://mydeviceinfo.comcast.net/) ---
**Author:** ![TonySinclair](https://avatars.discourse-cdn.com/v4/letter/t/49beb7/32.png) [@TonySinclair](https://boards.straightdope.com/u/TonySinclair)\ **Post date:** [December 30, 2012, 12:42am UTC](https://boards.straightdope.com/t/recommend-a-cable-modem/645531/3 "2012-12-30T00:42:17Z")
[http://mydeviceinfo.comcast.net/device.php?tier=-1&devid=294&e=0&d3=0&s=&so=&sc=1991](http://mydeviceinfo.comcast.net/device.php?tier=-1&devid=294&e=0&d3=0&s=&so=&sc=1991) I’ve been using this one for a little under a year, and it’s worked perfectly. I got it at Walmart for a little over a hundred bucks, IIRC. ---
**Author:** ![ExcitedIdiot](https://avatars.discourse-cdn.com/v4/letter/e/ea5d25/32.png) [@ExcitedIdiot](https://boards.straightdope.com/u/ExcitedIdiot)\ **Post date:** [December 30, 2012, 2:48am UTC](https://boards.straightdope.com/t/recommend-a-cable-modem/645531/4 "2012-12-30T02:48:42Z")
I did this about a year ago. I bought the Motorola sb5101 for $49, and broke even on the seventh month. Haven’t had a single problem with it. I haven’t even had to power cycle it yet. ---
**Author:** ![jacobsta811](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jacobsta811/32/2893_2.png) [@jacobsta811](https://boards.straightdope.com/u/jacobsta811)\ **Post date:** [December 30, 2012, 4:48am UTC](https://boards.straightdope.com/t/recommend-a-cable-modem/645531/5 "2012-12-30T04:48:25Z")
The Motorola SB 6120 and 6121 (I have a 6120) are quality equipment. The negative reviews on some of these are going to reflect on marginal signal quality coming through the lines at someones particular residence rather than issues with the modem themselves. If you have a DOCSIS 2.0 or earlier modem I wouldn’t hesitate to buy either one of them. Edit to add, whatever you buy, _don’t_ get a modem that isn’t both Docsis 3 and IPv6 compatible. As IPv4s become worth more, you might ultimately see providers giving only IPv6 public addresses, with IPv4 address being through a NAT layer. So it would be better for longevity. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [December 30, 2012, 4:52pm UTC](https://boards.straightdope.com/t/recommend-a-cable-modem/645531/6 "2012-12-30T16:52:18Z")
> [@ZipperJJ](#): > > Did you start here? [List of approved modems for Comcast.](http://mydeviceinfo.comcast.net/) I see that the SB6121 is on the list with three (the max.) stars. > [@TonySinclair](#): > > [http://mydeviceinfo.comcast.net/device.php?tier=-1&devid=294&e=0&d3=0&s=&so=&sc=1991](http://mydeviceinfo.comcast.net/device.php?tier=-1&devid=294&e=0&d3=0&s=&so=&sc=1991) > > I’ve been using this one for a little under a year, and it’s worked perfectly. I got it at Walmart for a little over a hundred bucks, IIRC. I’m using an Apple AirPort now. While it would be nice to have one less component on the shelf, I’m used to it and don’t need a wireless cable modem. > [@jacobsta811](#): > > The Motorola SB 6120 and 6121 (I have a 6120) are quality equipment. The negative reviews on some of these are going to reflect on marginal signal quality coming through the lines at someones particular residence rather than issues with the modem themselves. This is useful information. We have random dropouts in cable AV service, but it does not seem to affect the modem; so I suspect it is the cable box/DVR and not the signal.