DNS

i would like to manage my own DNS. Security is an important aspect on this network. My question is: Where should i put this service ? should i put the DNS on the firewall or it's better if i choose a standalone machine directly connected with the the internet ? Which security problems will i found with solution ? Internet ¦ ¦ ¦ ¦ DNS1 DNS2 ¦ firewall¦------DMZ-----web---Dbase ¦ ¦ LAN Thank You Alessandro adebe@inetlogistic.com