how to connect a linux box to ethernet/adsl modem

After further investigation. i have reached this position. Im hoping the following is a typical setup Im a bit confused over this one. linux---ethernet-->Modem=Alcatel Speedtouch Home --adsl--->internet You have an adsl/modem with an ethernet port. The isp is using pppoA. You can configure the modem using a web browser to setup ppp. so... how do u set up the linux box to talk to the internet throught the modem, do you set the modems ip as the gateway. Im confused because the manuals for win9x make you setup a vpn to the modem using pptp. dont like the look of that. you can set up the modem, as dhcp server. so perhaps you just use it as a gateway. ramble ramble thanks dids