cygwin warning:
  MS-DOS style path detected: C:\Users\labredes\Desktop\Cosas que he hecho\Seguridad\2. Ataques a nivel de red\Ataques sobre Ipv4\2. Escenarios\Ipv4 Alumno\project-files\dynamips
  Preferred POSIX equivalent is: /cygdrive/c/Users/labredes/Desktop/Cosas que he hecho/Seguridad/2. Ataques a nivel de red/Ataques sobre Ipv4/2. Escenarios/Ipv4 Alumno/project-files/dynamips
  CYGWIN environment variable option "nodosfilewarning" turns off this warning.
  Consult the user's guide for more details about POSIX paths:
    http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
