FTP (File Transfer Protocol) is an industry-standard protocol and user interface for transferring files between computer systems by means of a series of interactive commands. FTP involves a local client (software you execute to send or receive files) and a remote server (software elsewhere that responds to instructions from your client to accept or deliver files).

FTP features include:

  • Use of standard TCP/IP network protocols to move files between machines.
  • Support for transfers to or from nonUNIX systems as well as among computers running UNIX.
  • Use of IP host addresses as well as domain names to specify transfer targets.
  • Interactive login, usually with a password, to begin transfers to or from each remote machine (at LC, some transfers are preauthenticated to omit the password).

LC users with special file-transfer needs (such as for batch-oriented command files, extensive tracking of each transfer, or persistent transfers if network problems arise) may prefer to use the NFT file-transfer tool to move files among LC machines. See EZOUTPUT for a comparison of FTP and NFT. Users whose primary interest in FTP is as an interface to LC's High Performance Storage System (archival file storage) may want to consult the EZSTORAGE for helpful comparisons. For an alternative file-transfer tool that also relies on FTP software daemons to move files (but that offers special services beyond the basic FTP interface and that transfers to or from storage), see the HSI manual and the HTAR Reference Manual. If you prefer to FTP using a graphical user interface, then run Hopper on any LC production machine and select FTP from Hopper's Connect menu.

This manual explains how to run FTP and shows a typical FTP session. Standard FTP commands, as well as server replies and error codes, are easily searched online and are therefore not in this guide. On many LC production machines, a parallel FTP client (PFTP) is now the default, and parallel transfers occur automatically when they are possible. Instructions for invoking a nondefault nonparallel FTP client are also included here, along with advice on using jumbo-frame gigabit Ethernet links. Users who need to transfer files (to FIS) with their data encrypted can try Secure FTP, a special FTP client with very limited server support.

For help, contact the LC Hotline at 925-422-4531 or via e-mail (OCF: lc-hotline@llnl.gov, SCF: lc-hotline@pop.llnl.gov)