In the internet of things (IoT) and big data, the global information society is entering a new phase where consumers, networks, and perception devices work together more intimately. Software-defined networks (SDN) offer lower latency and massive connectivity for intelligent devices (IoT) for the internet of things. Smart communities are one of the most important applications of the blockchain. SDN technology is used to provide residents with smart services. Situational awareness for information security offers a distinct, high-level security perspective based on security alarm occurrences. However, contemporary information security warning data has become too complicated and varied than a simple analysis is almost impossible. In addition to enhancing IoT security's monitoring, emergency response, and forecasting capabilities, this article presents an IoT-assisted information security situation awareness framework (IoT-ISSAF). SDN model has been validated through simulation as being able to accurately assess the current state of network security in blockchain.