VPN from windows 10 computer behind ipfire firewall

I connected ipfire to my home network as a firewall. Workstations have Windows10 OS. From my workstation I was able to connect to a remote computer via VPN, which is part of windows 10. After connecting ipfire, this connection does not work. Does anyone know where the problem may be? Subnets are different (192.168.x.x vs 10.0.x.x), I connect to a public IP address. This connection works when I connect through a mobile operator or by bypassing the ipfire firewall. Can anyone advise on the settings? Thank you.


No idea?
When trying to connect a laptop with Windows OS 8 the system reports - Error 800: The remote connection was not made because the attempted VPN tunnel failed. The VPN server might be unreacheable. If this connection is attempting to use an L2TP / IPSEC tunnel, the secutiry parameters required IPSEC negotiation might not by configured properlytly.
VPN server is available (ping)
I assume this is a port opening error (PPTP TCP port 1723 or GRE Port 47, L2TP port UDP 1701, IKE port UDP 500 and 4500). How to configure a firewall to make VPN work? Can anyone advise?