fortigate blocking access to gateway/modem

[#1]

We have a 100A, which has been working well for some time, in conjunction with a cable modem. A couple weeks ago, we upgraded our cable account to a higher grade, with 6.5meg download 768k upload, and a static ip. This involved replacing the standard cable modem with a modem/gateway/router, supplied by Comcast. All seemed OK until this afternoon, when, all at once, we were without access to the internet. I couldn' t access my modem/gateway, not even to ping it. Comcast could http into it however. The couldn' t telnet into it until I unplugged the power to the 100A. Comcast tells me that the problem is on my side, but I wonder. Does anyone have comments/suggestions? John

[#2]

I would double check all of the basics. If the IP changed on any interface make sure any rules that reference it are changed also. If you remove the Fortigate from the picture and things work, it has to be blocking something. If you need to prove it another way, add an " Any Any" rule temporarily and see if traffic flies. You could also turn logging on and see what the rejected traffic is.

[#3]

Thanks, I tried those things you mentioned, with no luck. I finally got someone from Comcast on the phone, who was able to determine it was on their end. Their gateway firewall had turned itself on, blocking everything in all directions. John