I have been using monowal for a long time and I have never had problems, 
in my organizacion already we have mounted 4 making functions of VPN 
server, IPSEC to server an firewall; and Monowall competes with commercial 
much but expensive products.
all right, everything to gone well until I have had to form one with the 
interface WAN in DHCP; when formed interface WAN of this way, I cannot 
connect one PPTP VPN.
I have realized that the problem has to do with the renovation of the 
direction of that interface.
it has happened to him to somebody? 
as it is the solution?