Zyxel prestige 600 series

[ntleukin1985]

This modem is connected to Computer that is connected to LAN. And if this computer is turned off, the internet on other computers

is disconnected. How can i connect this modem to provide an internet to other computers, even if the Server is off.

[valentin.ene]

You need an gateway device which can be a standalone router or an computer running special software. Depending what is your expectations about this device you may take a look at some soho routers from Linksys (the cheap solution and the simple one) or you may buy a more powerful device like Cisco routers. If you want to use a dedicated computer for this service I advice you to use a Linux SO specially designed for router service, like IPCop or SmoothWall