4 month later I found a way. It's rather complicated but maybe it can help some of yours.
I bought a server in another country. I put gentoo on it. I made a permanent connection between my network and the server wich give me an internet connection (with vpn). My computer is directly linked to my new server so evrything goes throw it. I also used Nat to be able to acces all i want and to be accesible but I think it's maybe not needed, some test will reveal it. I just unlocked the ports (wich i though was used by lfs) on my gentoo server but .. it doesnt worked
So i just open a large range of ports on my server and it worked. Is not maximum of security but ... i dont care. LFS need some concesions.
Here is a little schem (simplified) to help the understanding:
[ My computer ] --(direct link)--> [ Gateway ] --( vpn )--> [ New Server ] ----> Internet
So everything is encapsuled into the vpn connection (wich was made default in routing table only for my computer using submasking network to give me my network into the network). LFS react as i was directly connected to internet.
I also must pass throw a filter but the filter can't handle an encrypted vpn so it just let it pass (off course i used an open port). I was glad to f**k this filter
So here it is, i can play all the online games i want. Offcourse it's working under windows but my lfs under linux work too. Its doesn't matter wich Os is running and it's a good point. I think i've told evrything. If help needed just ask but i thnk there is not much people in my case