A DMZ (demilitarized zone) in cybersecurity is a specially configured subnetwork that sits between an organization’s internal network and an untrusted external network, typically the internet, to provide an additional layer of security. The DMZ acts as a buffer, isolating public-facing services—such as web, email, and FTP servers—from the internal network where sensitive data resides.
Key features of a DMZ
• Segmentation: The DMZ separates external-facing servers from internal resources. Only the services exposed in the DMZ are accessible from the internet, while the internal network remains protected behind firewalls.
• Controlled Access: Traffic between the internet and the DMZ, as well as between the DMZ and the internal network, is tightly controlled and filtered by security gateways, typically firewalls.
• Risk Reduction: If a server in the DMZ is compromised, attackers still face additional security barriers before reaching the internal network, minimizing potential damage.
• Common Use Cases: Hosting web servers, mail servers, FTP servers, DNS servers, and proxy servers that need to be accessible from the internet but should not have direct access to sensitive internal data.
Purpose and Benefits
• Enhanced Security: Adds a critical layer of defense by ensuring that external entities cannot directly access sensitive internal systems.
• Compliance: Helps organizations meet regulatory requirements by limiting exposure and centralizing monitoring of externally accessible services.
• Damage Limitation: Reduces the risk and impact of successful attacks by containing them within the DMZ.
Architecture
A typical DMZ is positioned between two firewalls: one separating the internet from the DMZ, and another separating the DMZ from the internal network. This setup ensures that incoming traffic is scrutinized before reaching internal assets