As a security wise, what is the risk on farm of servers(database or application)UNIX or MicroSoft OS,if i connect them to internet behind firewall (PIX OR ELSE) on internal interface,with access-list deny all traffic from anywhere except one internet user on dmz,what about viruses,worms..etc???is there any advice or recomendation to do ?????what can i do on the main point access (internet router) as a first step for defense ????