How to set up a VPN server behind a router?

Question

VPN

VPN is raised on Windows 7 by standard means. The ports tcp 1723, udp 1701, 4500, 500 are forwarded on the router.
When connecting PPTP on the client, it writes error 806 - something like GRE could not be forwarded. Port 47 can't really be forwarded because there is no protocol (only TCP, UDP, and Other). Created 47, Other - see above.
Through L2TP IPsec writes "it is not possible to find the certificate". I didn't do it. That is, you can only connect from the machine to which the certificate is manually copied? To me, this is inconvenient. I would like to connect by name and password.
And, in general, which is safer? PPTP is also encrypted (sort of). Nowhere is this explicitly specified.

Answer 1

pptp is also supposedly encrypted, but this encryption has been completely broken for a long time. Google to the rescue.
If this is an under-router that does not allow you to specify the protocol number, such a router is in the firebox.
Pure IPSec allows the use of both passwords and certificates and a dash of bald. About l2tp/ipsec - I do not know.

Answer 2

PPTP - no encryption.
L2TP/IPSec allows both password (and key) and certificate authentication.
Raising a VPN server using Windows 7 is not very correct after all. If you need remote access to the server, then it is better to upgrade to a VPS or buy an external VPN with the ability to connect multiple accounts at the same time. and internal mesh. Then the server will not glow outside.