I've had cable network access through Comcast in Seattle for the past 18 months with nary a problem. Two weeks ago I lost all network access. After a fruitless half an hour on the phone with Comcast support it was determined that I had a faulty cable modem (which turned out to be complete bullshit - and I suspect the engineer knew it) and I should swap it out. Ok. Did that. Having plugged in the replacement modem, lo and behold, no browser access. I could ping sites with no problem and I appeared to have reasonable DNS setting etc. Very strange. I placed a call to Comcast (with the usual we'll call you back in 30 mins response) and left my PC directly connected to the Cable modem. Wandering past the machine a few minutes later all of my Firefox tabs I was using to connect to Yahoo, Google, Amazon etc were all now sporting a comcast.net account registration page. Odd - since I've been registered with Comcast for 18 months.... Anyway, humoring the system I went through the badly-designed and excruciatingly slow registration process. Ah ha! now I have browser access. Problem solved. The phone rang with my Comcast call back. No help needed here thanks! Done.
I plugged the cable modem back into my router (remember, the one that had been working fine for 18 months), connected to the router (Linksys) and went to look at the IP, DNS etc setting served by Comcast. Nothing. Zip. Zilch. WTF? Went back to the PC I registered with - all OK. Tried a different PC directly connected to the cable modem. Nothing working there.
Ah.... it all finally makes sense. Comcast don't like you running your own router (they'll sell you their router and access for up to 5 PC's - but you're not allowed to do that yourself). I must have been running under the radar for the past 18 months, someone must have looked at my traffic patterns and reset my account so that when I re-enabled I'd trigger their new security measures that locks your account to a single PC (via the MAC). Yeah - well screw you Comcast. Two minutes worth of MAC address cloning and I was back up and running on my own router. It's rather like the water company saying you can have a water feed - but you can only dispense from one faucet.... Now I know why Comcast stock is trading at the same point they were trading in July 1999. Actually the main reason that I'm pissed with Comcast is that even after asking both support engineers with whom I spoke (and to whom I described my home set up) neither of them flagged the fact that my connection would be locked to the activating-PC and that I could no longer use my own router (ha! that's what they think). Either they didn't know (would figure - given how crappy Comcast is at support - seen their on-line FAQ's recently?) or they knew and were told to keep quiet about it. Dimwits.
Oh, any for any Comcast folks reading this, go fix your packet shaping software that keeps screwing up and turning into traffic "denying" software. Thanks.