An overview of FTP

By, Indhurani C

Contents Introduction to FTP Objective Communication and data transfer FTP login facilities Syntax Security issues FTP commands FTP reply codes List of FTP clients List of FTP servers Conclusion

Introduction to FTPFTP – File transfer protocol in the application

layerStandard network protocol Authenticate- clear text sign in protocolCommand line applications – The first FTP

clientSecured transmissions –SSL / TLS

Objective Sharing of files Indirect use of remote computersProtect the user from variations in file

storageTransfer of data reliably & efficiently

Communication and data transferThe server responds,3- digit status codeOptional text messageEg: 200 OK

Contd…FTP may run in two modes,Active modePassive mode- PASV command

Data representationsTransfer data over network,ASCII Image/binary modeEBCDIC modeLocal mode

Contd…ASCII- Used for text Image/binary mode- byte transactionsEBCDIC mode- 8 bit character encoding used

in IBMLocal mode- sends data in proprietary format

Data transferData transfer can be done in three modes,Stream modeBlock modeCompressed mode

Contd…Stream mode - continuous stream of dataBlock mode – several blocks namely block

header, byte count and data field.Compressed mode- data is compressed

using run length encodingRun- length encodingEg. wwwwbbwwbbw-4w2b2w2b1w

Login CredentialsFtp login-username and passwordUsername –USER commandPassword –PASS commandNo login credentials-Limited access

Anonymous FTPUsername- “anonymous”Password- e-mail IDNo verification is done

Firewall TraversalFTP transfers data only after getting

permission from serverFirewall blocksPASV command

SyntaxFTP, URL syntax is described as, ftp://[<user>[:<password>]@]<host>[:<por

t>]/<url-path>

For example: ftp://

public.ftpservers.example.com/mydirectory/myfile.txt

Security IssuesBounce attacksSpoof attacks.Brute force attacksPacket capture

Secure FTPFTPSSFTPFTP over SSH (not SFTP)

FTPSFTPS is an extension to the FTP standard that

allows clients to request that the FTP session be encrypted.

AUTH TLS command. The server has the option of allowing or

denying connections that do not request TLS.

SFTPSFTP, or secure FTP, is a program that uses

Secure Shell (SSH) to transfer files.Preventing passwords and sensitive

information from being transmittedFTP clients cannot be used to talk to an SFTP

server

FTP over SSH (not SFTP)FTP over SSH (not SFTP) refers to the

practice of tunneling a normal FTP session over an SSH connection

No confidentiality or integrity protection

List Of FTP CommandsGETABORDELEPASSAUTHRNTOPWDMODEALLORMD

FTP Reply Codes3-digit codeThe first digit is used to indicate one of three

possible outcomes—success, failure or to indicate an error or incomplete reply

2yz4yz or 5yz1yz or 3yz

Contd…The second digit defines the kind of error:x0z – Syntaxx1z – Informationx2z – Connectionsx3z – Authentication and accountingx5z – File systemThe third digit of the reply code is used to

provide additional details.

LIST OF FTP CLIENTSCyberducklftpgftpFireFTPFileZilla

CyberduckThe developers of the cyberduck are David V.

Kocher, Yves Langisch Java language.Cyberduck is an open source FTP and SFTP

client for Mac OS X and WindowsSupports FTP/TLS- using “AUTH TLS”

command.

FireFTP It is developed by Mime ČuvaloFireFTP is a free, open source, cross-platform

FTP client for Mozilla Firefox in the form of an add-on.

It supports FTP, FTPS, and SFTP. FireFTP runs on platforms that Firefox

supportsFireFTP is activated from the Tools menu,

opening a two-pane view within a Firefox window

gftpgftp was developed by Brian MasneygFTP is an open source multithreaded FTP

client.Used on Unix-like systems, such as Linux,

Mac OS XSupport for the FTP, FTPS ,HTTP, HTTPS and

SFTP protocols

lftp lftp was developed by Alexander V. Lukyanov lftp is a command-line file transfer program

for UNIX and Unix-like systemssupports FTPS, HTTP, HTTPS, HFTP , FISH and

SFTP by specifying the desired protocol in a location URL

Features -location bookmarks and resuming downloads.

List of FTP serversRobo-FTP serverFileZilla serverEFT serverComplete FTP

Robo-FTP serverRobo-FTP Server is a secure, automated

Windows FTP server It supports FTP, FTPS, and SFTP connections. It offers event-driven automation for

encryption, decryption, zip, unzip, move, copy, delete, email notification, database operations

CompleteFTPCompleteFTP is a proprietary FTP server for

Windows that supports FTP, FTPS, SFTP, SCP, HTTP and HTTPS

Features -Protocol translation (e.g. from FTP to SFTP, or FTP to FTPS)

Remote administration

The recent products of FTP client and server,Cute FTPTurbosoft FTPSmart FTPFTP rushWing FTP server

ConclusionThus the ftp client and server play a major

role in transferring file from the client and server.

The emerging products of FTP client and server will transfer the file effectively.

Referenceshttp://www.wingftp.com/http://

en.m.wikipedia.org/wiki/File_Transfer_Protocol

http://www.ftprush.com/http://www.cuteftp.com/http://www.turbosoft.com/

THANK YOU