Nowadays smart Internet of Things (IoT) devices are used briskly, and these devices communicate with each other via wireless medium. However, this increase in IoT devices has resulted in a rise of security issues associated with the IoT system. Therefore, an intrusion detection and prevention system (IDPS) is used to locate and report any malicious activity. The IDPS's feature selection (FS) task is necessary to improve the data quality and decrease the data used for classifying intrusive traffic. Therefore, this paper proposes a novel FS method that hybridizes improved salp swarm algorithm and harris hawk optimization algorithm. The XGBoost classifier is used for classifying reduced network traffic. Proposed system demonstrates high accuracy and low computation time, surpassing other related approaches used for the IDPS feature selection task.