\begin{thebibliography}{10}

\bibitem{iptables-tutorial}
Oskar Andreasson.
\newblock Iptables tutorial.
\newblock http://iptables-tutorial.frozentux.net/iptables-tutorial.htm.

\bibitem{nessus}
Renaud Deraison.
\newblock {\em {Nessus Vulnerability Scanner}}.
\newblock http://www.nessus.org/about/.

\bibitem{Drake}
Joshua Drake.
\newblock {\em {Linux Networking HOWTO}}.
\newblock LDP (Linux Documentation Project), 2000.

\bibitem{DHCP}
R.~Droms.
\newblock {\em Dynamic Host Configuration Protocol}.
\newblock http://www.ietf.org/rfc/rfc2131.txt, March 1977.

\bibitem{Forouzan.TCP/IP}
Behrouz Forouzan.
\newblock {\em {TCP/IP Protocol Suite}}.
\newblock McGraw-Hill, 2000.

\bibitem{Ports}
IANA (Internet Assigned Numbers Authority),
  http://www.iana.org/assignments/port-numbers.
\newblock {\em {The well known ports number}}.

\bibitem{Nmap}
Insecure.Org, http://insecure.org/nmap/.
\newblock {\em {Nmap}}.

\bibitem{Kurose-Ross-3}
James~F. Kurose and Keith~W. Ross.
\newblock {\em {Computer Networking: A Top-Down Approach Featuring the Internet
  (3rd Edition)}}.
\newblock Addison Wesley, 2005.

\bibitem{Lathi}
Bhagwandas~Pannalal Lathi.
\newblock {\em Introducción a la Teoría y Sistemas de Comunicación}.
\newblock Limusa Noriega Editores, 1994.

\bibitem{Oppenheim.Discrete}
Alan~V. Oppenheim and Ronald~W. Schafer.
\newblock {\em Discrete-time signal processing}.
\newblock Prentice Hall, 1999.

\bibitem{Oppenheim}
Alan~V. Oppenheim, Alan~S. Willsky, and S.~Hamid Nawab.
\newblock {\em Señales y Sistemas (2a edición)}.
\newblock Prentice Hall, 1997.

\bibitem{packet-filtering-HOWTO}
Rusty Russell.
\newblock {\em {Linux 2.4 Packet Filtering HOWTO}}.
\newblock
  http://www.netfilter.org/documentation/HOWTO/packet-filtering-HOWTO.html.

\bibitem{Shannon}
Claude~E. Shannon.
\newblock {\em The Mathematical Theory of Communication}.
\newblock University of Illinois Press, 1963.

\bibitem{SSH}
SSH Communications Security Corp, http://www.rfc-editor.org/rfc/rfc4251.txt.
\newblock {\em {RFC 4251. The Secure Shell (SSH) Protocol Architecture}}, 2006.

\bibitem{SSH-UAP}
SSH Communications Security Corp, http://www.rfc-editor.org/rfc/rfc4252.txt.
\newblock {\em {RFC 4252. The Secure Shell (SSH) User Authentication
  Protocol}}, 2006.

\bibitem{SSH-TLP}
SSH Communications Security Corp, http://www.rfc-editor.org/rfc/rfc4253.txt.
\newblock {\em {RFC 4253. The Secure Shell (SSH) Transport Layer Protocol}},
  2006.

\bibitem{SSH-CP}
SSH Communications Security Corp, http://www.rfc-editor.org/rfc/rfc4254.txt.
\newblock {\em {RFC 4254. The Secure Shell (SSH) Connection Protocol}}, 2006.

\bibitem{Stallings-7}
William Stallings.
\newblock {\em {Comunicaciones y Redes de Computadores (7a Edición)}}.
\newblock Prentice Hall, 2004.

\end{thebibliography}
