I'm trying to setup a VPN between 2 machines over an internet connection. Both machines are behind routers. I found a bunch of FAQs on the topic but whenever I try to connect I get error 800. Do you need any info to help me diagnose this problem?
VPNs can be finicky and problems regarding them are often very unique and specific to a particular device, OS, or software solution. Individual Routers have various methods of passing VPNs, sometimes you can just poke a hole with port forwarding, other times you need to find that specific routers check box to allow VPNs.
Celestra provided a good link and here's another VPN error 800
The guys at howtonetworking have some good tips and on that page you may find some resolution that will help, but there are also additional links on that page which you might very well find more helpful. Good luck and keep us posted, your solution, when found may prove helpful to other members.