ValueMentor Segmentation Security Testing is a professional service that validates network isolation and segmentation controls through penetration testing methodologies. The service evaluates whether network segments are properly separated and whether traffic can bypass intended security controls. The testing process includes scoping and asset mapping to identify critical assets and network topology, reconnaissance and data gathering to analyze network architecture and communication flows, policy and firewall validation to examine rules and configurations, active exploitation testing using tools and manual techniques to scan for vulnerabilities and misconfigurations, lateral movement simulation to test attacker pivot capabilities across systems, and reporting with remediation guidance. The service addresses PCI DSS segmentation validation requirements for cardholder data environment isolation, meeting annual merchant and semi-annual service provider compliance needs. It includes firewall and ACL review to detect misconfigured rules, VLAN and boundary validation to confirm secure separation, architecture security analysis to evaluate network design alignment with Zero Trust principles, and breach containment assessment to measure how segmentation controls limit breach impact. The testing aims to prevent lateral movement, strengthen threat containment, reduce audit scope, and support regulatory compliance requirements across finance, healthcare, retail, and other industries handling sensitive or regulated data.