>is it the WAN port ?
>what are the necessary setting that I have to perform on the router ( internal external IPs) ?
Usually none. Read the book.
>do I have to set up a DHCP server on one of the PCs ?
Usually no. The router has a DHCP server. Read the book.
>How about if I decied to leave the router and use an 8 port switch , is it going to work even if the switch doesn't need any setting ? can I just hook up:
DSL Modem----> Switch------> PCs
That won't work unless you obtain an IP from your ISP for each PC. Many ISPs charge by the month for additional IPs. The router shares one ISP-provided IP address with a NAT. See http://duxcw.com/faq/ics/waysshare.htm and http://duxcw.com/faq/ics/diffrout.htm for more info. Larry