\begin{frame}[fragile]
\frametitle{openVPN}
\begin{itemize}
\item based on Transport Layer Security (TLS/SSL)
\item support Routing and Bridging
\item Authentication:
  \begin{itemize}
  \item Pre-shared Keys (PSK)
  \item Username/Password
  \item Based on certificates
  \end{itemize}
\item Pros:
  \begin{itemize}
  \item flexible configuration
  \item easy integration in existing Network infrastructures (e.g. NAT)
  \item high security level
  \end{itemize}
\item Cons:
  \begin{itemize}
  \item None
  \end{itemize}
\end{itemize}
\end{frame}