\documentclass{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
  \draw[red] (-4,4.5) -- +(1,0) node[right,node font=\tiny] {incoming};
  \draw[orange] (-4,4.25) -- +(1,0) node[right,node font=\tiny] {rtable 1};
  \draw (-4,4) -- +(1,0) node[right,node font=\tiny] {rtable 0};
  \node (wg0)      at (0,0) {wg0};
  \node (vio0)     at (0, 2) {vio0};
  \node (pf)       at (4, 2) {pf};
  \node (client)   at (-4, 2) {client};
  \node (internet) at (0, 5) {internet};
  \draw (-1, 2.5) rectangle (5,-0.5);
  \node (server)  at (2,2.7) {VPN Server};
  \draw[->,red] (client) -- (vio0);
  \draw[->,red] (vio0) -- (pf);
  \draw[->,orange] (pf) -- node[above,sloped] {NAT} (wg0);
  \draw[->] (wg0) -- (vio0);
  \draw[->] (vio0) -- (internet);
\end{tikzpicture}
\end{document}
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