The optimal thing for your client is to do both, establish a DMZ and use NAT.
A DMZ is a logical concept also known as a screened subnet. It sits between the Internet and your internal network's defense, usually some combination of firewalls andbastion hosts.
Typically, a DMZ contains devices accessible to Internet traffic, such as Web (HTTP ) servers, FTP servers, SMTP (e-mail) servers and DNS servers. A very basic DMZ is accomplished using routers that route traffic according to your established rules.
NAT is a protocol, there are no rules per se. It enables a LAN to use one set of IP addresses for internal traffic and a second set of addresses for external traffic. A NAT box located where the LAN meets the Internet makes all necessary IP address translations.
NAT serves three main purposes:
Provides a type of firewall by hiding internal IP addresses.
Enables a company to use more internal IP addresses. Since they're used internally only, there's no possibility of conflict with IP addresses used by other companies and organizations.
Allows a company to combine multiple ISDN connections into a single Internet connection.
Your Sonicwall Pro 100 allows you to establish a special DMZ port that provides Internet access
to network servers. Servers on the
DMZ are publicly accessible, but they are protected from attacks such as SYN Flood and Ping of Death. Use of the DMZ port is optional.
Sonicwall Pro 100 in the NAT Enabled mode translates the private IP addresses on your network to the sngle, valid IP address of the SonicWALL. Your DMZ may also may also be operated in the NAT Enabled mode.
The Sonicwall Pro 100 will handle your security concerns easily administartion is also very easy.
