I had a 3120 that use to work fine when i try to use PPTP VPN Passthrough. This router use to have just a simple IPSEC vpn to my main office. I've change that VPN tunnel to have VPN ip sec with GRE and router ospf protocol. Now, I cannot use PPTP VPN passthrough to connect to my others client networks. Does any one know of any conflict of VPN IPSEC with GRE and PPTP VPN passthrough? I'm using the built in Windows PPTP one.