Comcast XFINITY → Motorola SBG6580 DOCSIS 3.0 Wireless Cable Modem Gateway

ya you don't want a combo CM/Router unit you'll just be asking for trouble

you won't be able to update your router's firmware yourself so if it needs updating your stuck

I don't see the point in spending a $150 for this product anyways. It would have to drop a good amount before I would even consider it. Plus Motorola can't even get a stable firmware out on there 6120, on certain equipment setups. So why would you trust them to put out a good firmware for both a modem/router together lol. As the guy above also mention, more problems to troubleshoot when they are both together, and no way of puting any custom firmwares on the router side.

Listen to you guys. Because you have had difficulties in the past with OTHER devices, you suggest not dealing with this one? Ridiculous. Your attitudes are not very conducive toward making technological progress which is indeed unfortunate. I'm glad you don't work for me.

I had no issues with my 6120 when i had it. I did however have many issues with my motorla 4200 cable modem when it came out. Opening up too many connections would freeze the modem. (edonkey, online gaming) I still let comcast over all these years give me motorola modems. att broadband would not fix so if you where on back in the att broadband forum back when this was happening, you might remember it. Hell, my instructions where archived online!

»sbmodem.tripod.com/

Funny part was by updating your firmware manually, you can actually unlock your speeds too. I was really worried about getting into trouble from people uncapping their modems by my instructions. Nothing happened and att eventually updated the firmware.

WARNING FOR VPN USERS ::
Note that I just received my 6580 today.
Went to set up the VPN and a page would not appear
in the modem admin interface page in a browser.
Called Motorola.
They did some fast talking but I am a Cisco Certified engineer so they finally admitted the VPN is not finished in the firmware and asked me to call back in two weeks.
Unbelievable that they knowingly sell an unfinished modem.
Called Cox and told them they had better spread the news around Cox support as the calls will be flooding in.
They said they certainly would.

I bought an SBG6580 at Best Buy a couple days ago, and have it working and supported by Comcast right now. Yes it is on the compatibility list (or was when I checked 2 days ago).

Right now my problem is, I keep losing internet. It may be a problem in the modem or their support for it, I am not sure yet. I did buy this modem because I'd been having problems with the prior one (SB5120), which I now suspect *may* be a line problem.

Am not sure yet; I spoke with a Comcast rep who seemed knowledgeable and she checked 3 other modems (unknown make/model) on my node, saying they were not having similar problems. But mine has lost and rebuilt connection 27 times in about 30 hours! However probably 5-6 of those are from me rebooting the modem for various settings experiments.

I'm playing with different settings now and also experimenting with aiming a fan at the SBG6580 on the off chance it's some heat related problem. Might take it back to BB and exchange for another. Will follow up with more information when I have it.

I would suggest starting your own thread and posting this info: »Comcast High Speed Internet FAQ »How To Get Help!

I am with Brighthouse and 2 modems later kept having disconnects.. finally they installed the old crappy SMC but it maybe garbage but at least my internet stays working. Motorola routers right now seem to be total and utter garbage. The SBG6580 reading all over it won't stay connected. DHCP protocal event log says not a valid format.. so denied DHCP address.. hence no internet.

Apparently I did receive a dud modem. I exchanged it for another SBG6580 today, and it has now been online for about 9 hours without any problems.

It does get pretty warm when it's running - warmer than I recall the SB5120 ever getting.

I had good experiences talking with the Comcast reps, though they are unfamiliar with this very new-model modem/gateway. They say they've been getting great results and reliability with the SB6120, for what that's worth.

All in all it seems like a pretty good modem to have. They're flying off the shelves at my local Best Buy in Bellevue, Washington - there were more than 20 when I bought my first one on Monday; today when I made my exchange, I grabbed their last one.

(Beachintech: I wasn't asking for help; just reporting my experiences with this new modem.)

This is my final followup - my (replaced) SBG6580 has now been online about 24 hours and has been very solid. My smokeping from dslreports is steady: »/r3/sm ··· 0f&r=728

Internal networking via the included 10/100/1000 4 port switch has been fine. A wireless-n laptop about 8 feet from the device is getting a solid connection listed at 300Mbps; one that is 2 floors away (on the third story of my stick-built home) is getting 107Mbps on its wireless-N card.

So that's the good. As for the bad, I will say, the modem does seem to take awhile to lock on with Comcast and start moving packets. The Comcast person will say the modem is up and running but there will be about 5 more minutes before packets start moving.

Also the documentation seems light, both the included PDF and the onboard help pages. Some options are explained very poorly; some not at all.

All in all I am happy with the modem and I have a hunch that the firmware (including the docs problem I just mentioned) will only improve in time.

I will followup with more information if I detect any further issues with this modem. quux out!

So has anyone used both this new modem and the old SBG901.. it seems from most accounts this new one is not of the same quality and I may as well just go with the older 2.0 model.. especially since my service is only up to 10Mbps anyway.

I had the SB901 for about 5 years without any problems, worked like a champ. I purchased the SBG 6580 about three weeks ago and it's dead. Called Cox, they could see the MAC, but no IP. It worked great for three weeks and was consistently pulling 40Mbps without issues.

The wireless is not up to par compared to the 901. I have an Xbox with 802.11n wireless and I'm using WPA-2 PSK and I could only play online for about 30 minutes before I lost all wireless connectivity and had to reboot the modem.

Cox Tech came out today and verified that the SBG 6580 was dead, it would acquire upstream and downstream channels, but never would receive a WAN IP. We tried everything, but eventually re-provisioned my old 901 and things were great. I'll be going back to BestBuy...glad I saved the box and documentation.

I am having the same problem with the SBG6580. It will drop the connection several times an hour. Comcast support was little help saying they can "see" the modem from their end and "must be a problem on my end".

Hello, I am using the SBG6580 on a none Comcast network.
I wanted to just share what I have been seeing.

I have a 50 mbps down and 5 mbps up service, and my speeds have been great! I am really enjoying the speeds!
I bought my modem at Best Buy, but not sure if you could supply your own modem if you were a normal customer.

I had issues with the DDNS feature, and the support at Motorola told me to turn off the firewall on the modem (just a check box) and that feature would start working, that did fix the DDNS issue. I also am having issues with the VPN, I can get it to work but it stop working after awhile and even though I can reconnect to the vpn no traffic works, also all other NAT port forwards stop working. Motorola did not have a fix for this.

I asked Motorola if they had any firmware updates for these modems yet, and got this response from Motorola

Cable Service Providers or MSO's control the firmware on the cable modems. Any and all firmware upgrades to your Motorola cable modem, or any DOCSIS cable modem, is completely under the control of the cable operator. Motorola does not, nor is capable of, controlling the firmware upgrade process. You should contact your cable operator for details or issues with their plan to upgrade your cable modem.

I explained that I bough the modem from Best Buy, and I would think the cable provider would not be responsible for updating my modem, since I own it.

Can some share with me how this works? I work for a cable company and I can get the updates from them if need be, but this just sounds strange to me, if you own the modem especially one that has all these type of features in it, it would be nice to be able to update the modem myself to get features such as VPN working that my cable provider is not worried about supporting at all.

Other than the things I mentioned above, the modem has been working fine, I turned off the firewall and my DDNS works fine now, and I just have not used the VPN anymore (wish I could) but the modem stays online and speeds are great, wireless seems fine so far but I dont use N at all yet, and dont use G much.

Thanks! I was having the same problem with DDNS and this fixed it for me also.

I currently own the SBG 9000 wireless and quite happy with it.
Have zero problems, but thinking about upgrade. Suggestion to turn off the firewall may be accepted only to be a temporary solution and it is a bit odd to hear this from the manufacturer. It looks like the firmware fix is due.

To bad it does not sound like Motorola feels they owe me anything, instead they think I need to work this out with me cable provider.

Or, you could just get a better stand alone modem and a nice router and not have these issues.

I do not see what this really has to do with it being a combined modem/router-gateway, but right now my cable provider only supports this Motorola modem and a Ubee for Docsis 3.0, they are both modem/gateway type devices.
It seems to me the problem here is not that this is a modem/gateway, but that Motorola's support of this device is completely different (like they dont support it at all) than what I am used to in a normal gateway product like Linksys or Netgear etc..
I can get the firmware updates in other ways, I know people that work with Motorola etc.. but I was wondering how a normal customer that bought a modem like these from Best Buy would handle this issue?

The modem/router worked fine on Comcast, but I returned it because it did not allow for a custom DNS server. And I was loathe to use Comcast's since any error URL would take me to search.com.

If you have comcast, there are many more modems that are supported. If you don't, than this is the wrong forum for you.

It is a shame you returned it because it doesn't allow for a custom DNS server. I have the SBG6580 and I use a custom DNS server--I just set the custom DNS address in my computer, so the computer doesn't use the modem's auto-DNS feature.

just to add my random 2cents... i have had the MOTO SBG6580 within weeks of them being available and haven't had one problem with mine. it has worked consistently and it is a fairly complex setup. but i would never recommend this modem to anyone who needs it to cover even half of a duplex which is already half a house. in our half of the duplex i only get a solid signal within a 20-25' +/- radius. i do get sinal out to 300 or so feet but it connects, drops, connects, drops constantly. i got it when i upgraded my net that needed the DOCSIS 3.0 from a Linksys WRT-600N and separate older surfboard DOCSIS 2.0 (where i would get full signal well into a 600' distance away). thought, yay, it would be one less piece of junk in my house. well i'm reverting to the WRT-600N and just a plain MOTO DOCSIS 3.0 modem.

that has ZERO to do with a modem or anything in this post.....yea its the same modem, but thats it...different plant, different system...levels have nothing to do with if thew modem will work on comcast....

Moderator Action
The post that was here (and all 3 followups to it), has been moved to a new topic .. »Slow Charter Speeds