# An Adaptive Security Framework for Internet of Things Networks Leveraging SDN and Machine Learning
## 1 Introduction
Additionally, following standard security best practices, such as least privilege access, vulnerability management, and network segmentation, helps create layers of defense [12]. Given the wide spectrum of security threats faced by IoT systems, a holistic and multidimensional approach is essential to provide comprehensive protection. Securing IoT environments necessitates defense-in-depth approaches comprising several security measures that are in place to protect against different attack vectors. Sealing the risks posed by threat actors requires an IoT security framework that incorporates various security concerns like confidentiality, integrity, authentication, access control, and adaptive response approaches. The neighbor discovery protocol (NDP) is a crucial protocol that is included in the IPv6 protocol suite. Its tasks include discovering the MAC address associated with an IPv6, rerouting packets from one router to another, duplicate address identification, finding routers on the network, and address resolution. NDP uses several ICMPv6 message types to conduct its functions, including neighbor solicitation (NS), neighbor advertisement (NA), router solicitation (RS), and router advertisement (RA). Security is a top priority due to NDP's inherent vulnerabilities in address resolution and auto-configuration, which attackers might exploit to infect devices, intercept traffic, or overload networks. Some of the main risks are traffic hijacking through the marketing of fake network prefixes, MITM attacks that impersonate address resolves, and the flooding of NS or NA messages. The exponential rise in IoT devices has rendered IPv4 obsolete, and in its stead is the new protocol, IPv6. One benefit of IPv6 is that it has vast address space (3.4 \(\times\) 10\({}^{38}\)), which makes it possible for the IoT to grow. This is because, for IPv4, 128-bit addresses are accessible rather than 32-bit addresses. By enabling auto-configuration, which allows devices to automatically generate IP addresses based on announcements from router prefixes, assigning IP addresses to IoT devices is considerably simpler. IPsec capabilities are necessary for IPv6 in order to ensure end-to-end security with improved authentication and encryption. Enhancements also provide better mobility, making it easier for deviceslike mobile phones to roam between different networks while maintaining connections. Additionally, IPv6 has streamlined processing with fixed-length packets and simplified headers, resulting in more efficient packet handling compared to IPv4. However, potential drawbacks of IPv6 include larger packet sizes, immature implementations with bugs, and the loss of NAT, which can expose devices to more threats. The nuances of IoT communication merit protocols that are expressly designed with the intricacies of embedded devices and diverse networking mediums in mind, unlike conventional IP networks. IETF groups like 6 lo and ROLL continue advancing open standards that smooth the integration of massively scaled IoT with the common internet infrastructure. As IoT permeates society and industry, standardized and interoperable protocols will grow even more crucial. Forward-thinking technical foundations like IPv6, 6 LoWPAN, RPL, and related standards aim to fulfill that mission, delivering the communication capabilities necessary to unlock the possibilities of a connected world. Table 1 shows some of the key communication protocols used in IoT networks:  
The main research question addressed is how to design a comprehensive security framework that can dynamically detect and mitigate a wide range of attacks in IoT environments while maintaining availability and quality of service.