DMZ (computing) - Rationale

Rationale

In a computer network, the hosts most vulnerable to attack are those that provide services to users outside of the local area network, such as e-mail, web and Domain Name System (DNS) servers. Because of the increased potential of these hosts being compromised, they are placed into their own sub-network in order to protect the rest of the network if an intruder were to succeed in attacking any of them.

Hosts in the DMZ have limited connectivity to specific hosts in the internal network, although communication with other hosts in the DMZ and to the external network is allowed. This allows hosts in the DMZ to provide services to both the internal and external network, while an intervening firewall controls the traffic between the DMZ servers and the internal network clients.

A DMZ configuration typically provides security from external attacks, but it typically has no bearing on internal attacks such as sniffing communication via a packet analyzer or spoofing such as e-mail spoofing.