# Connection Problems With Comcast, Linksys, and Clearwire



## shellycarebear (Apr 16, 2008)

I currently have comcast as my ISP. last year it started going down every day..usually around the same time. Comcast came out, exchanged the modem and it still had the same problem. they checked the box outside, replaced all the cables and made sure everything was in working order. 
i also replaced my router (linksys) as well as my network connection card. 
theres no adware or spyware affecting it. 
since i work from home and need my internet to work, i got clearwire as a back up. for about 6 months it worked fine, now it has the same problems. it goes down. 
whenever i call either comcast or clearwire they say its working perfectly, but i just cant connect. usually it comes back on its own within a few minutes, sometimes i have to reset everything. 
now its getting worse again and happening several times a day. i have again called comcast and clearwire. they say each works fine. i even got a new clearwire modem. 
my firmware is up to date and the ip address looks normal. 
i am at a total loss of how to proceed because it seems that everything has been replaced.
oh ya and the strangest thing. when i use clearwire, the comcast works fine for the rest of the house (2 other computers) when i use comcast, if mine goes down, so does the rest of the house. it seems to be originating from my computer some how, but im not sure what is causing it or how to fix it. 
any suggestions would be greatly appreciated. im at my wits end of what to do other than buying a whole new computer (not really feasible at this time)


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## icrman (Apr 19, 2008)

I posted about this sort of thing. You need to do the MAC address clone feature in the router.


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## johnwill (Sep 26, 2002)

Comcast does NOT key off the MAC address of the connected machine, they authorize the DOCSIS modem by it's MAC address. This is not the issue, and every router on the planet has a MAC address clone feature anyway.


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## stif_NEC (Apr 23, 2008)

Yo, I'm new here. The MAC clone feature is usually used by routers on setting up a cable ISP connection. 
Anyhow, I'm curious, have you tried connecting your computer directly to the modem and see if the connection there is stable(try it in a day)? If it is, then the problem would be on the router part. Since you mention you have tried upgrading the Firmware of the router . You may want to setup the MAC clone feature and setup MTU size (preferred size 1500,1400,1300 set to manual) if you know to access the web utility of the device, i think you can access that using you browser (IE,firefox etc), and go to http://192.168.1.1 (I think, correct me if I'm wrong) no username password admin.

Inform me if this helps or not. Thanks, gambatte!!! (means good luck or do your best in japanese).


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