What Is FTP?
FTP stands for "file transfer protocol." FTP powers
one of the fundamental Internet functions and is the prescribed
method for the transfer of files between computers. It is
also the easiest and most secure way to exchange files over
the Internet.
An FTP address looks a lot like an HTTP or web site address
except it uses the prefix ftp:// instead
of http://.
What is a Protocol Anyway?
The dictionary
defines the word "protocol" as:
"A set of conventions governing the
treatment and especially the formatting of data in an
electronic communications system."
Therefore, FTP is essentially a "set of
conventions" that can be used by an "electronic communications
system" to transfer files.
These "conventions" are defined in a
document known as
RFC 959. This document contains the details of how FTP
should be implemented in software.
If you want to write some software that
implements FTP, then
RFC 959 would be a good place to start.
What are some common uses of FTP?
The most common use of FTP is to download files. FTP is
vital to the MP3 music sharing, most online auctions
and game enthusiasts. The ability to transfer files quickly
and reliably is essential for everyone creating and maintaining
a web page.
How can I use FTP?
- Most web hosting services provide FTP access to their
customers to allow them to upload the contents of their
web sites.
- Companies often have FTP servers that allow users to
send and receive files.
- Most universities have FTP servers that allow their
students to download course materials and upload assignments
for submission.
- Use FTP to transfer files among users, especially if
the files are too large to attach to an email.
- Use FTP to browse through a collection of downloadable
files on a public software archive.
What is an FTP Server?
Typically, a computer with an FTP address is dedicated
to receive an FTP connection. A computer dedicated
to receiving an FTP connection is referred to as an FTP
server or FTP site.
What Is HTTP, and can I use it to transfer files?
HTTP (hyper-text transfer protocol) was primarily designed
to transfer text such as HTML (hypertext markup language)
or web pages. HTTP can be used to transfer files; however,
it’s not as useful for uploading or sending files
as it is for downloading them.
What do I need to start using FTP?
You need two things to begin using FTP:
1. An FTP client application and
2. An FTP server.
Where can I get an FTP Client?
Most computer operating systems already come with an FTP
client; however, it is not user-friendly. Start
up a command prompt window, type "ftp" and
then press “enter.” Chances
are you will be greeted by an "ftp>" prompt.
Unless you are well-versed with using command lines and
enjoy typing, there are much easier ways to FTP.
FTP Explorer is an FTP client application. It
is designed to make FTP simple and hassle-free. Most people
agree it is much easier to use than a command line FTP
client. Download FTP Explorer
here.
Where can I get an FTP server?
In many cases, the FTP server you want to connect to is
already out there somewhere, waiting for you to establish
a connection to it.
If, however, you want to set up your own FTP server so
other users can connect to your server and transfer files,
you have a few options:
- Many operating systems come with an FTP server, but
it is often disabled for security reasons. Windows
XP Pro includes an FTP server as part of Internet Information
Server, but it is disabled by default. Most Unix and
Linux systems include FTP "daemons" as part
of their distributions. Check with the vendor of
your operating system to determine if you already have
FTP server software.
- There are also a variety of third party FTP servers
available.
How do I publish my web site to an FTP server?
You need to send your web site files to the FTP server
that your web hosting service has established for you.
Obtain the following information from your hosting service:
1. Host name or IP address of their FTP server,
2. The login name you should use,
3. The password you should use, and
4. The location of the folder where you should store
your files.
How do I upload files?
To upload files, you must first be connected to an FTP
server using the appropriate login and password (most
servers do NOT allow anonymous users to upload). Contact
the administrator of the FTP server to determine the
appropriate login information.
Once connected, you must navigate to the proper folder. You
may not have rights to upload into every folder to which
you have access. Contact the administrator of the
FTP server to determine the folder that you should be uploading
to.
Once connected and in the proper folder, you have several
options for uploading at your disposal:
A. Upload Menu Option
1. Choose the FILE | UPLOAD menu option
2. Select file(s) to upload from the Upload dialog
box
B. Upload Toolbar Button
1. Select the Upload toolbar button
2. Select file(s) to upload from the Upload dialog
box
C. Drag and Drop
1. Open a windows explorer view, such as My Computer
2. Navigate to the files that you wish to upload
3. Drag and drop the files onto the right pane of
FTP Explorer
NOTE: Drag and drop is currently the only way to
upload entire folders.
What is Anonymous FTP?
Many FTP servers allow "anonymous" access. Usually these
servers will only allow you to download
anonymously and will prohibit uploading.
To connect with an anonymous FTP
server:
1. Use "anonymous" for the login name
2. Use your email address for the password
What is PASV mode?
An FTP session generally consists of two connections
between the client and the server.
The first connection is known as
the "control connection" and is used by
the client to send commands to the server and receive
responses from the server. This connection is usually
made via TCP port 21.
The second connection is known as
the "data connection" and is used to
transfer the actual data (such as files or directory
listings) between the client and server.
The client establishes a control
connection to the server and logs in. Subsequently, client
submits a transfer command (such as RETR, STOR, or LIST),
that requires a data connection to be established.
Normally, the client will specify a TCP port that the
server should connect to, and the server will then
initiate a connection back to the client on that port and
begin transferring the data. Many modern firewalls and
routers will block this connection by default, as it is
generally a security risk for a client to accept
connections. This is where PASV mode is useful.
When PASV mode is used, the client
sends a command to the server informing the server of its
intent to use PASV mode, and the server responds with a
TCP port. The client then initiates a connection to the
server on this port and the server begins transferring
data.
In general, it is usually better to
use PASV mode.
SOME BASIC TERMS TO KNOW
Anonymous FTP: Transfers files from the
public portion of an FTP server. "Anonymous" means
that you don't have to have an account on the server. In
most cases, use anonymous as your user name and your email
address as your password.
Archive: An FTP site that contains a
selection of files for download.
Download: Also called "Get".
Copy a file from an FTP site to another computer. If you're
merely downloading shared files an anonymous account is
usually sufficient. However, if you're downloading Web
pages for update, a password and user privileges is usually
required.
FTP site: A Web site that stores files
for download. You can access the sites with a Web browser
by typing in the address. All FTP site addresses begin
with ftp:// (instead of http://).
Upload: Also called "Put".
Place files on an FTP server. Upload privileges are usually
password protected to keep unauthorized users from placing
files that could contain viruses or other malicious code
on the server. |
