If you are having problems with your Comcast business gateway blocking websites or other strange behavior, you may need to disable the Smart Packet Inspection.
The Smart Packet Inspection system is designed to prevent TCP flood attacks but many times it will block legitimate traffic.
I have had to disable it at many client locations after they would have certain websites stop working and the only way for them to fix it was to reset the Comcast modem.
The first step is to go to 10.1.10.1 in your web browser.
You should be able to connect even if you have your own router setup behind the Comcast gateway.
Username is cusadmin, password is highspeed
After you login, head to the firewall page:
Make sure “Disable Gateway Smart Packet Detection” is checked and hit apply.