I have been having problems with my internet since I swapped out my modem for a Comcast modem. I was having problems with web pages loading slowly, incompletely, not at all, slow internet speeds, etc. After a lot of investigation I narroed the problem down to a bug in the ARRIS TG3482G Comcast modem.
When setting the router to bridge mode it should fully disable the firewall so that when you connect your router to the modem you are not running two (Double NAT firewalls. Running two hardware firewalls will cause network issues like slow speeds, packet loss, etc. That was exactly what I was expierencing. Before enabling bridge mode set the SB6 firewall to "Custom" with no boxes checked. This disables the firewall. I contacted Comcast numerous times about my internet acting up. For around 2 months. They could not figure out what it was. I was also expierencing loss of connection completely because of a seperate issue. This problem with the connection issue left me serviceless for the last 2 months. Since I do not have cable boxes and stream my TV stations I could not watch TV on my Roku sticks. I am still fighting with Comcast to apply the proper credits since they said once it is resolved they will credit my account for the time affected.
If you set this modem to bridge mode it sets the firewall to "Low". Threfore, when you connect your router you are double NAT. I have taken two screenshots. One before making the change pinging the modem and one after pining the modem. On the first screenshot you can see I am expierencing timeouts and packet loss. On the second there is no timeouts and no packet loss. I wanted to submit this because I do no know where else to post or who to contact to fix it. It seams when I call support or use chat no one can seam to get me in touch with the right department for any reason. Also, they say they will have the right department call me the fallowing day and they never do. Hopefully, this will help someone else, or the right Comcast person will see it. Then, it can get resolved. Now I am dealing with an agent who is telling me I need a new modem to remove the History vault from my accout lol. She claims it will be shipped free of charge and it will be an XB7. I said as long as it is free and it is an XB7 because I actually like the XB6. The wifi just is terrible.
Thanks for posting this - another clue in the many hours to get my great new modem working that I did not want, but was required in order to get higher speed (even though my own one's spec's say it's fine). Will exit Bridge (again!) and try this.
Another word for the wise - disable WiFi BEFORE entering bridge mode, and use the Xfinity app to disable the open Xfinity wifi - otherwise you'll have the radio swamping channels, even though you cannot connect to it. Yes, another bug seems to lave the Wifi radio active even though bridge mode should disable it.
OP never returned. 5 month old dead thread now being closed.