Which technique involves probing all active systems on a network for running services?

Port scanning is a technique used to probe active systems on a network to identify open ports and the services running on those ports. By sending requests to various ports on a target system, a port scanner can determine which ports are responding and what services are associated with those ports. This information is critical for security assessments, as it helps in identifying potential entry points for attacks, understanding the exposure of systems, and evaluating the security posture of a network.

The ability to detect open ports allows security professionals to focus on securing those services and address any vulnerabilities that may be present. Tools that perform port scanning often provide additional functionalities, such as identifying the version of the services running, which can help in performing more detailed vulnerability assessments and prioritizing remediation efforts.

In contrast, the other techniques involve different aspects of security assessment and network management. IP probing is less specific in nature, primarily focusing on discovering which IP addresses are active on a network rather than the services associated with them. Network segmentation refers to dividing a network into smaller, isolated subnetworks to improve security and performance rather than probing for running services. Vulnerability assessment is a broader process that includes identifying and evaluating vulnerabilities in systems, which may incorporate port scanning as one of its techniques, but is not solely focused on probing