This user guide for ExtremeCloud™ IQ (Classic) version 25.5.0 provides comprehensive technical instructions for configuring, managing, and optimizing the Extreme Networks cloud-managed and locally managed networking environments. It details onboarding workflows for real, simulated, and Digital Twin devices, including Universal APs and Tunnel Concentrators, with support for advanced features such as Automatic Frequency Coordination (AFC) for 6 GHz spectrum compliance. The guide covers configuration of wireless and wired network policies, including SSID authentication (WPA2/WPA3, PPSK, MAC), VLANs, RADIUS, VPN services, and SD-WAN routing. It includes extensive guidance on device templates, BLE services, presence analytics, WIPS, and IoT profiles. Administrative functions such as license management, SSO integration with SAML-based IdPs, API token generation, and audit logging are documented. The document introduces ML Insights and the CoPilot dashboard for anomaly detection, client health scoring, and network performance analytics. Designed for IT professionals, the guide includes troubleshooting tips, configuration best practices, and support for advanced security, QoS, and firewall policies, with accessibility suited for experienced technical users.