Only LDAP client can get both L2TP and PPTP in Mountain Lion VPN service. Local client will only get L2TP and not PPTP.
So you have to configure your server with proper DNS and Open Directory and create Local Network User.
DNS will be very sensitive as you may facing problem to start Server Apps if the configuration is wrong.
Thank you for the answer.
Unfortunately that's what I've done. I have configuered Open directory, local network users, DNS.
I am sorry, but I propably don't understand what you mean LDAP, because in my opinion there is no method to set anything about LDA protocol in GUI of Server.app.
I agree that only local users can use L2TP and network users can use both of them.
As I said/writed, it looks for me that there is some problem with windows client, because:
1/ With same configuration and login (user,password) parameters even in same local network I am able to use VPN PPTP with MAC OS X client.
2/ When I try this again with same settings on windows client, it returns error in class 8xx, which frankly doesn't say much. And I don't see any connection attempts in Console.app.
Ok, I think I've solved this.
It seems that issue was made by editing registry LDAP Encapsulation with DWORD value "AssumeUDPEncapsulationContextOnSendRule"
It's probably some bug or maybe just incompatibility and this DWORD is changing something in structure of PPTP communication. I don't know actually.
However, I deleted this record and PPTP now works perfectly.