>copy tftp flash
>раз указываете что с флеша грузиться будете

Вот в том то и косяк что команды
copy tftp flash
нет
есть только:
  archive:        Copy to archive: file system
  bootflash:      Copy to bootflash: file system
  disk2:          Copy to disk2: file system
  ftp:         &n... to ftp: file system
  http:         &... Copy to http: file system
  null:           Copy to null: file system
  nvram:          Copy to nvram: file system
  pram:           Copy to pram: file system
  rcp:            Copy to rcp: file system
  running-config  Update (merge with) current system configuration
  startup-config  Copy to startup configuration
  syslog:         Copy to syslog: file system
  system:         Copy to system: file system
  tftp:           Copy to tftp: file system

Вот что выдает команда show file system

File Systems:

     Size(b)     Free(b)      Type  Flags  Prefixes
           -           -    opaque     rw   archive:
           -           -    opaque     rw   system:
           -           -    opaque     rw   null:
           -           -   network     rw   tftp:
     2095096     2088843     nvram     rw   nvram:
           -           -    opaque     wo   syslog:
*  256458752   208420864      disk     rw   disk2:#
    65536000    30800292     flash     rw   bootflash:
           -           -   network     rw   rcp:
           -           -   network     rw   pram:
           -           -   network     rw   http:
           -           -   network     rw   ftp:
           -           -    opaque     ro   tar:
           -           -    opaque     ro   cns: