# Software-Defined Networking: Categories, Analysis, and Future Directions
## 4 Network Security and Management
In [117], a network management approach called \"Smart-Net System\" is proposed in which each data plane device keeps a flow rule in its flow table. If a packet reaches the data plane for the flow rule that exists in the flow table, then it is forwarded to the controller. The controller verifies the behavior of that packet and takes preventive measures to avoid attacks. In [118], a software-defined security (SDS) architecture is presented that is open and universal. It offers an open interface for security services, devices, and management, which is quite helpful for network security vendors to implement network security products and solutions. In this research work, various attack types to which networks can be vulnerable are analyzed, which is helpful for disabling such attacks by modifying the security configuration mechanism at the server. The trend of increasingly massive IoTs and continuous streaming traffic is driving the demand for increasing computations. Cloud-fog hybrid systems support delay-intensive applications in a distributed computing manner. On the other hand, SDN supports various network infrastructures and inter-controller communication models (flat, horizontal, vertical, hybrid, or T-model) for distributed network management [119]. In addition, the vulnerability and consistency challenge in distributed architecture is more likely to be seen, in contrast to central control. Currently, to support the applications in 5G networks and beyond, the SDN distributed frameworks need to be more sophisticated [120]. [PERSON] et al. [121] proposed SmartBlock-SDN for efficient resource management and security assurance in blockchain-enabled IoT networks. The proposed framework addresses the challenge of distributed control security and energy-efficient cluster head selection in controllers. SmartBlock-SDN is mapped for a layered approach (IoT, edge, cloud), and cloud-enabled blockchain is considered to cope with the various common network vulnerabilities. Distributed homogeneous controllers and enforced network policies are recorded using immutable blockchains. This stored policy configuration can be accessed using the REST API for various operations in line with network security and resource management. To address flooding attacks, BSDNFilter and blockchain-enabled SDN is proposed in [122]. This work reduces the data packet violations in the SDN network. By employing trust-based filtration, the proposed works outperform a realistic industrial network against network security attacks. In [123], a BMC-SDN architecture is proposed to confine the SDN and blockchain in a network, where control is distributed for failure tolerance and redundant control resources. The proposed work employed blockchain for redundant controllers in various segregated domains. East/west (inter-controller) communication and network operations are recorded using blockchains. The resource management shortcoming of distributed computational resources (such as NFV, data centers, fog nodes at edges in fog computing) is that energy, storage, and computational resources are limited. With the increase of massive IoT, the 5G and beyond networks will employ more constraints in their resources. 5G mainly has three service use cases: ultra-reliable and low-latency (URLLC), massive machine type computing (mMTC), and enhanced mobile broadband (eMMB). In addition, 6G is a revolutionary initiative in the history of the wireless network, which promises to support a wide geographical region with ultra-high data rates, massive enabled IoTs, connected drones, virtual reality, and network autonomy (by leveraging the machine learning components in the pipeline) [124]. SDN softwarization, southbound interface, east/west interface and on-the-fly management aspects can support the 5G and 6G networks to support a wide area of applications and massive IoTs across the globe. The aspect of resource-limited nodes of edge networksrequires efficient resource provisioning in the network for QoS. [PERSON] et al.