# Software-Defined Networking: Categories, Analysis, and Future Directions
## 4 Network Security and Management
### Summary and Lessons Learned
Currently,SDN is lacking in this aspect because the network typologies are in flux in terms of making the SDN-integrated networks more scalable. \begin{table}
\begin{tabular}{p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline
**Studies** & **Techniques** & **Description** & **Strengths** & **Weaknesses** \\ \hline Advance reservation access control [110] & Ryu controller, OVS switches, ESNet 100 G SDN testbed & Guarantees exclusive access of network resources to a certain flow for which the user/app is authorized & Efficiently protects authorized flows from competing with the network traffic & Need to consider path computation and resource scheduling functions, QoS \\ \hline Verifying reachability [111] & Z3 version 4.4.2, Intel Xeon processors with 256 GB of RAM & Verifies reachability by slicing complex networks into small networks according to the network-wide verifications & Provides tool to verify networks in the presence of middleboxes & Middlebox code is not verified, which can affect network traffic by sending packets to invalid interfaces \\ \hline Systematically troublesnot networks [112] & OpenFlow, TCAM that provides a operating correctly & Helps network administrators to troublesnot bugs and their root causes to verify that networks are operating correctly & Provides a useful tool to troublesnot bugs and their root causes & Does not suggest integrating the program semantics into network troubleshooting tools \\ \hline SRV [113] & Floodlight, Java, OpenFlow App & Forwards warning messages and refuses the identified flow rule instantly on detection of malicious flow rules & Helpful to detect malicious flow rules & Only discusses priority-based mechanism; other attack scenarios should be analyzed \\ \hline SDN-Actors [114] & Erlang, Scala, Akka, OpenFlow & Models network applications using actors and verifies various correctness properties via existing model-checking mechanisms & Offers framework to model and verify SDN programs using static and dynamic verification tools to validate network behaviour & Proposed mechanism only tries to uncover programming errors by checking only the SDN program \\ \hline Reverse update [115] & Python, OpenFlow switch, naive controller & Ensures maintenance of flow rules characteristics during the transition time & Provides a technique to preserve flow rule properties during the network policy change & Lacks an investigation of the effects of network policy change by analyzing packet violations \\ \hline SVM [116] & Mininet emulator, Floodlight controller & Support vector machine (SVM) algorithm is utilized to judge the traffic and carry out DDoS attack detection & Detects DDoS attacks in SDN to enhance network security & Although this research has the ability to detect DDoS attacks of ICMP traffic, it is less efficient \\ \hline FUPPE [127] & iFogSim, MATLAB R2018a, OpenFlow protocol & Security enhancement against TCP SYN flood attacks in fog nodes via SDN paradigm & Node trust profiling & Fault tolerance not considered \\ \hline Security architecture [128] & Mininet-WiFi/ethernet, Openday light & Secure and energy-consumption-aware communication in cyber-physical systems (CPS) & Transactional alteration localized using blockchains & No real testbed, only simulation-based evaluation \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Summary of network security and management.