Since two weeks we have a second ISP in our office. to connect the two cables to one server (the DC) we bought an extra internet box with two wan adapters. also did set up the thing that with NAT and port forwarding it all works now. However, some users cannot connect with VPN anymore. most still can so I have been checking what it can be but so far i am clueless. I've noticed that some L2TP users receive an 809 error, PTPP will lead the user to 806 which is related to GRE packages. Other users do receive a 619 error which what i understand is quite broad. Since most users still can connect successfully, I wonder if it is the internet box we set up in between or is it something else? Could it be simple thing as only limited connections are allowed at one time? It also happens with disabled firewalls and with a home pc. Both windows XP and Windows 7. The VPN Server is a Windows 2003 server.

I am not certain I understand the configuration but if at the server site you have two NAT devices in series that can Block GRE and other VPN traffic.Rob Williams