K, problem fixed with the help of our Internet Provider. Some steps where missing.
Here are what needs to be done in order to deactivate NAT on our speedtouch.
Public IP addess of our Router: 18.104.22.168
Public IP addresses availables for our company: 22.214.171.124 to 126.96.36.199
I will set the router address to 188.8.131.52 and our Linux server (Https, mail etc..) to 184.108.40.206 (mask 255.255.255.248 or /28)
– set Up the router like the usual way. Make sure it works.
– unplug DSL cable
– ppp ifdetach intf=Internet
– nat ifconfig intf=Internet translation=disabled
– ppp ifconfig intf=Internet unnumbered=enabled
– ip ipadd intf=LocalNetwork addr=220.127.116.11@28 addroute=enabled
– ppp ifattach intf=Internet
– exit than reboot speedtouch.
On our Linux Server:
ifconfig eth2 18.104.22.168 netmask 255.255.255.248
route add default gw 22.214.171.124
Then, it works.
All Internet requests will be directly assigned to our public ip address 126.96.36.199 (for example extranet.mycompany.com), and it will directly go to our linux server.
Thanks for your forum. Informations here are incredibly interesting.