DNS HINFO (Host Information) records provide information about the hardware and operating system of a host. While these records are part of the original DNS specification, they are rarely used in modern networks due to security concerns about exposing system information publicly.
HINFO records contain two text strings: one describing the host's CPU/hardware type and another describing the operating system. These records were originally intended to help with network management and optimization by providing information about the capabilities of different hosts on the network.
Examples of HINFO records might include "INTEL-386" for the CPU field and "UNIX" for the OS field, or "AMD64" and "LINUX" for more modern systems. The format is flexible and can accommodate various hardware and software combinations.
HINFO records fell out of favor primarily due to security concerns. Publishing detailed information about host hardware and operating systems can provide valuable intelligence to attackers, helping them identify potential vulnerabilities and target specific systems more effectively.
Modern network security practices generally discourage the public disclosure of system information that is not absolutely necessary for normal operations. The potential risks of exposing this information typically outweigh any benefits from having it available in DNS.
Today, system information discovery is usually handled through application-specific protocols, configuration management systems, or secure network management tools rather than public DNS records. This approach provides better security while still enabling necessary system administration functions.
Here's what an HINFO record looks like for the domain example.com:
