This article focuses on the security of the MQTT protocol in Internet of Things (IoT) applications, highlighting critical vulnerabilities such as authentication, encryption, privilege escalation, denial of service, and improper QoS (Quality of Service) handling. To enhance security, an IoT test environment was designed and an Intrusion Detection and Prevention System (IDS/IPS) based on Suricata was implemented. The methodology involved setting up a test environment with a Mosquitto broker and various tools for network data capture and analysis. Simulated attacks were conducted to evaluate the effectiveness of the IDS/IPS in detecting and mitigating threats, including topic manipulation and malicious traffic flooding. The results showed that the proposed IDS/IPS system effectively detects and mitigates most attacks without significantly impacting system performance. Despite its effectiveness, limitations such as the need for manual adjustments to detection rules were identified. The study suggests that integrating additional techniques, such as machine learning, could enhance threat detection and extend protection to other emerging IoT protocols. This solution offers a practical, resource-efficient alternative for strengthening security in IoT environments.