TFTP(1)

NAME
tftp - trivial file transfer program

SYNOPSIS
tftp [-e] [host] [port]

DESCRIPTION
tftp is the user interface to the Internet TFTP (Trivial File Transfer Protocol), which allows users to transfer files to and from a remote machine. The remote host (and optional port) may be specified on the command line, in which case tftp uses host (and port) as the default for future transfers (see the connect command below).

The optional -e argument sets a binary transfer mode as well as setting the extended options as if tout, tsize, and blksize 65464, had been given.

The Multicast TFTP option is supported in open-loop (i.e., "slave-only") mode based on IETF draft-dion-tftp-multicast-option-01.txt (May 2002), which in turn was based on RFC2026.

COMMANDS
Once tftp is running, it issues the prompt ‘tftp’ and recognizes the following commands:

? command-name ...
    Print help information.

ascii
    Shorthand for "mode ascii"

binary
    Shorthand for "mode binary"

blksize blk-size
    Set the tftp blksize option to blk-size octets (8-bit bytes). Since the number of blocks in a tftp get or put is 65535, the default block size of 512 bytes only allows a maximum of just under 32 megabytes to be transferred. The value given for blk-size must be between 8 and 65464, inclusive. Note that many servers will not respect this option.

connect host-name [port]
    Set the host (and optionally port) for transfers. Note that the TFTP protocol, unlike the FTP protocol, does not maintain connections between transfers; thus, the connect command does not actually create a connection, but merely remembers what host is to be used for transfers. You do not have to use the connect command; the remote host can be specified as part of the get or put commands.

get filename
get remotename localname
get file1 file2 ... fileN
    Get a file or set of files from the specified sources. Source can be in one of two forms: a filename on the remote host, if the host has already been specified, or a string of the form hosts:filename to specify both a host and filename at the same time. If the latter form is used, the last hostname specified becomes the default for future transfers.

mode transfer-mode
    Set the mode for transfers; transfer-mode may be one of ascii or binary. The default is ascii.

put file
put localfile remotefile
put file1 file2 ... fileN remote-directory
    Put a file or set of files to the specified remote file or directory. The destination can be in one of two forms: a filename on the remote host, if the host has already been specified, or a string of the form hosts:filename to specify both a host and filename at the same time. If the latter form is used, the hostname specified becomes the default for future transfers. If the remote-directory form is used, the remote host is assumed to be a UNIX machine. If you need to specify IPv6 numeric address to hosts, wrap them using square bracket like [hosts]:filename to disambiguate the colon.

quit
    Exit tftp. An end of file also exits.

rexmt retransmission-timeout
    Set the per-packet retransmission timeout, in seconds.

status
    Show current status.

timeout total-transmission-timeout
    Set the total transmission timeout, in seconds.

tout
    Toggle the tftp "timeout" option. If enabled, the client will pass its retransmission-timeout to the server. Note that many servers will not respect this option.

trace
    Toggle packet tracing.

tsize
    Toggle the tftp "tsize" option. If enabled, the client will pass and request the filesize of a file at the beginning of a file transfer. Note that many servers will not respect this option.

verbose
    Toggle verbose mode.

HISTORY
The tftp command appeared in 4.3BSD. IPv6 support was implemented by WIDE/KAME project in 1999. TFTP options were implemented by Wasabi Systems, Inc., in 2003, and first appeared in NetBSD 2.0. Multicast TFTP was implemented by Jared D. McNeill in 2006, and first appeared in NetBSD 4.0.

SECURITY CONSIDERATIONS
Because there is no user-login or validation within the TFTP protocol, the remote site will probably have some sort of file-access restrictions in place. The exact methods are specific to each site and therefore difficult to document here.