1. user mode  user>
2. privileged mode   router#
   3. global configuration mode  router(config)#
   4. other modes (int, router, route-map, line, etc.)
   5. setup mode    yes/[no]?
6. Rxboot mode  (password bypass/recover)

sh ver   [0x2102]
sh flash [check available flash space]

sh run
sh star 
sh access-l