# Multi-Constraint and Multi-Policy Path Hopping Active Defense Method Based on SDN
## 5 Experiment and Result Analysis
### SDADM Effectiveness Experiment  
#### 5.1.1 Diversity of Path Hopping  
In the generation of the existing path hopping space, there is a phenomenon that the constraints are too strict, which limits the scale of the path hopping space, reduces the diversity of path hopping, and causes the hopping path to be reused in multiple hopping periods. This section proves the superiority of this scheme in enhancing the diversity of path hopping through the analysis and comparison of the three schemes of a traditional network without path hopping, PSM-ARM (adaptive route mutation based on path state matrix) and the SDADM designed in this paper. The experiment sets \(\alpha\) to 0.5, \(\beta\) to 5, \(A\) to 10, \(X\) to 20%, and sets all the bandwidths in the path to 100 Mb/s. H1 and H2 communicate at a rate of 10 Mb/s, the other hosts in the network communicate normally, and the path hopping situations of the three communication modes in multiple hopping periods are compared without considering attacks and bandwidth. The experimental results are shown in Table 2.  
As can be seen from Table 2, in the traditional mode without path hopping, the communication path is fixed, which is very susceptible to attacks, and attackers can listen to complete data at any node on the path. PSM-ARM pursues the path without any repeated points. Although it effectively avoids key nodes, it reduces the scale of path hopping and the diversity of path hopping. Furthermore, in the process of path selection, there is no constraint on the time of use, so it is very easy to repeat the use of paths in multiple cycle  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \begin{tabular}{c} **Hopping** \\ **Strategy** \\ \end{tabular} & \begin{tabular}{c} **Hopping Period** \\ \end{tabular} & \begin{tabular}{c} **Communication Path** \\ \end{tabular} & \
\begin{tabular}{c} **Whether the Path** \\ **Changes** \\ \end{tabular} &
\begin{tabular}{c} **Whether** \\ **Reused** \\ \end{tabular} \\ \hline No path hopping & 1 & (OF-S1, OF-S3, OF-S7, OF-S9, OF-S12) & No & Yes \\ \hline \multirow{5}{*}{PSM-ARM} & 1 & (OF-S1, OF-S4, OF-S8, OF-S11, OF-S12) & Yes & No \\  & 2 & (OF-S1, OF-S3, OF-S7, OF-S9, OF-S12) & Yes & No \\  & 3 & (OF-S1, OF-S4, OF-S8, OF-S11, OF-S12) & Yes & Yes \\  & 4 & (OF-S1, OF-S2, OF-S4, OF-S6, OF-S10, OF-S12) & Yes & No \\  & 5 & (OF-S1, OF-S3, OF-S7, OF-S9, OF-S12) & Yes & Yes \\ \hline \multirow{5}{*}{SDADM} & 1 & (OF-S1, OF-S5, OF-S8, OF-S11, OF-S12) & Yes & No \\  & 2 & (OF-S1, OF-S2, OF-S4, OF-S3, OF-S7, OF-S9, OF-S9, OF-S12) & Yes & No \\ \cline{1-1}  & 3 & (OF-S1, OF-S5, OF-S8, OF-S10, OF-S12) & Yes & No \\ \cline{1-1}  & 4 & (OF-S1, OF-S3, OF-S7, OF-S9, OF-S12) & Yes & No \\ \cline{1-1}  & 5 & (OF-S1, OF-S3, OF-S4, OF-S6, OF-S10, OF-S12) & Yes & No \\ \hline \hline \end{tabular}
\end{table}
Table 2: Experimental results of path hopping diversity.  
Figure 3: Network topology.  
hops. SDADM calculates all paths between two points, and through the constraints of similarity and usage time, it enhances the diversity and unpredictability of hopping while expanding the path hopping space. Moreover, as the network scale and \(L\) value increase, the difference in the number of paths between SDADM and PSM-ARM will be greater, which greatly expands the path hopping space and enhances the diversity of path hopping.