# LSSDNF: A Lightweight Secure Software Defined Network Framework for Future Internet in 5G-6G
## 1 Introduction  
The 5G/6G network is separated into the 5G/6G network architecture sections: the control layer, the access layer, and the forward layer [1]. This architecture separates user data from the control plane from the user plane only through the access and forwarding layers. In contrast, the control layer performs a logically centralized network control role. The access layer covers a wide range of wireless technologies and network configurations. Based on a common hardware platform, the forward layer can ensure high reliability, minimal delay, and average load of the service data flow. Blockchain-enhanced Software-Defined Networking refers to a network controlled by a central entity or software used by all the network resources. With an SDN, the control is moved from the network layer to the application layer, dividing the data plane from the control plane. It has numerous advantages over a traditional network, including lower costs, improved security, more flexibility, easier configuration, and prevention of vendor lock-in. A secure framework for SDN can allow a network manager to change the way the network devices, i.e., Routers and Switches, handle packets by enabling complete control of the rules set into network devices from a central console. The mobility of devices in wireless networks has an effect on communication services. The controller can solve position changes in horizontal switching by detecting geographic locations, and it can also somewhat enhance vertical mobility and offer load balancing. Although there is no mobility, the controller can nevertheless locate an alternative route in the event of a failureand balance the traffic between nodes. Some researchers have brought up these issues; however, there are not many workable answers. Wireless networks have become more virtualized and sophisticated with 5G/6G. While there are significant security flaws in the topology of conventional wireless networks, 5G and 6G promote infrastructure sharing. Even if the widely accepted hypotheses are true, their plausibility is diminished in networks with a large number of adaptive sensing devices. Additionally, the virtualization trend will provide many unknown difficulties. The variables that affect a network's quality include bandwidth, Jitter, propagation time, throughput, and latency. One of the most significant is Jitter, which typically causes reduced network throughput and, in certain situations, network congestion that sometimes results in total network failure. The market for Secure-SDN technology is expanding as all the major multinational corporations--including Google, Facebook, and Amazon--adapt to it and change their traditional networks. Traditional networks are now more sluggish, risky, and expensive. Software-Defined Networking with blockchain, on the other hand, enhances network connectivity for sales, customer support, internal communications, and document sharing. This job is in high demand since it integrates blockchain and SDN. SDN enables complete network control, enabling quick responses to change network or business requirements. By converting them to a Secure Framework for Software Defined Networks, this work focuses on improving the scalability, efficiency, and security of the current Traditional Networks. By dividing the network into three layers--the application layer, control layer, and forwarding layer--traditional decentralized networks converted to centralized SDN networks. These layers each play a part in enhancing the scalability, efficiency, and security of the network. Routing attacks change how packets are routed on the SDN by manipulating routing control information. In order to keep the network secure from routing attacks, the data of the SDN network, such as routing information, including IP addresses and MAC addresses, are stored on a blockchain utilizing multichain.