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
.
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
NetBSD2.0.
Multicast TFTP was implemented by
Jared D. McNeill
in 2006, and first appeared in
NetBSD4.0.
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.