Actually we are trying to use monowall with both vpn and a captive
portail 
but unsuccessfully surfing through a remote proxy
 
Lan 1 : captive portal
Wan : adsl
Lan 2 : private lan
 
The  vpn connect the lan2 with a remote lan where there is a proxy
server.
 
The vpn works correctly 
A pc on the lan2 can ping the proxy (so the vpn works well)
And all the firewall rules are open.
 
But impossible to surf through the remote proxy on internet.
The 3131 port is used by the proxy.
 
So what should I do to configure correctly monowall ?
Should I do something that I miss ? or don't understand ?
 
Thanks by advance for the help.
 
vincent