Question : VPN connection issue with Comcast

I have a customer with a Comcast home connection. She previously had an cable modem router combo. We were having problems establishing a PPTP VPN connection. I replaced the device with a RCA cable modem and a separate router. Even with the computer plugged directly into the cable modem (the computer had a public IP), I was unable to pass GRE (IP protocol 47) packets. Does anyone know if Comcast might be blocking GRE in the central NJ area for home users?

I used PPTP ping to test this and the GRE packets failed.  I tried from another Internet connection and it worked without issue.

Answer : VPN connection issue with Comcast

Comcast does not block GRE (protocol 47) packets.  I live in Southern NJ and connect via VPN to an office in Central NJ every day.


Have you tried any other troubleshooting steps?