I am have dificulty setting up a vpn connection. My VPN Connection works on the internal network. I cannot connect via VPN from a public IP address. I get a error message in regards to GRE . I checked the cisco router internal it is passing through 1723 and protocol 47. The ISP Bell in cannada says they are not blocking anything. My logs in the event viewer say a vpn connection was made but could not complete due to GRE.
Your Help is greatly appreciated.