I have had consistent problems with my internet connection since installing internet with Comcast on 6/11/12.
I signed up for the 50 Mbps service (Extreme 50). I have no other Comcast services. An XFINITY wireless Gateway (ARRIS model TG852G/CT) was installed in my home and configured by the Comcast service technician.
However, 25 to 50% of the time that I try to access an internet site, the browser does not connect with the site and I get the browser header “HTTP 403 Forbidden” or “HTTP 404 Not Found,” and many times, but not always, the IP address is filled in with
This can happen with any site including common sites such as Google, GoogleNews, etc. If I close page and try again and again, the site will connect sometimes after 2-5 attempts. If I click on a link in a page, the same thing may happen. It happens less if I click “open in a new tab.” When I open a page with lots of images such as Google news, many of the images don’t show up and have small x’s in them suggesting the image sites could not connect even though the page opened.
This problem happens on all wireless connected devices: a windows 7 laptop, a windows XP laptop, windows 7 desktop, and an IPad. ( I have not configured my devices except for entering the name of the wireless network and the encryption key.) It also happens on the windows 7 desktop when I connect to the gateway with an Ethernet cable instead of with the wireless.
I tested changing the DNS servers on the IPad to the Google servers 126.96.36.199 and 188.8.131.52 as suggested in a thread with others having this same problem:
The modem isn't provisioned correctly. Call 1-800-COMCAST (1-800-266-2278) or 1-800-XFINITY (1-800-934-6489) and ask them to fix it. If you get no joy, you can contact Steve Teow (AKA ComcastSteve) via twitter, private message via these forums or by email.
Thank you for your help. I called 1-800-XFINITY on the evening of 6/16/12 and explained the problem and your suggestion. The service person was very knowledgeable. He tried to reset the modem twice but it did not solve the problem. He then confirmed that the Gateway was in captiveportal status but could not remotely release it because he got the error message the MAC address was invalid (although he had had me confirm it was the correct MAC address on the back of the Gateway). He created a job ticket to have the modem activated by someone with more authority on the network and said the problem should be solved within 72 hours. He said I might be contacted by Comcast and to call back if the problem was not fixed.
4 days later nothing had changed. I had not heard back from Comcast.
I called XFINITY/Comcast again. This service person could review the notes from the last call. She confirmed that the Gateway was still in captiveportal status. She said she could send a technician. I asked that he bring a new Gateway since it seemed to me that the Gateway or its initial software installation was malfunctioning and could not be fixed remotely. The technician was scheduled for the next day.
The service technician on time with a new Gateway. He was skeptical that it would fix the problem since he thought it was an account problem. He installed a new Gateway (SMC model SMCD3QMV this time.)
The Gateway activated normally. The internet connection performed flawlessly. Got speed on speed test of 50Mbps. No captiveportal messages. All devices connected including Ipad and Xbox 360 and performed as expected.
I notice that Comcast has now placed a warning message about the original ARRIS Gateway model they provided me on the DOCSIS Device Information Center page regarding software malfunctions with third party DNS. My Gateway did not function with the Comcast DNS.