Back to product page

Protocol property


Determines protocol used for connection.

Type

Protocols enumeration

Syntax

  • C#
  • VB.NET
Protocols Protocol {get; set; };

Property Protocol As Protocols

Remarks

There are 3 most used protocols supported in wodFtpDLX.NET (and additional subtype). Most known, FTP protocol is old plaintext protocol. Typically, clients connect to port 21 on the server and issue commands over so called control connection. Once data needs to be transferred, FTP protocol requires also additional data connection to be opened, where large amount of data is sent/received. Clients can optionally choose whether they will use so called 'active' or 'passive' transfers - determining who will initiate data connection (and who will accept it, of course). You can set Passive property to select one of these options. This protocol is NOT encrypted, and is insecure.

FTPS is also known as FTP/S or FTP-SSL protocol, or even explicit FTPS protocol. Control connection is always encrypted using SSL layer between socket communication, and data actually transferred by the application. Protocol is pretty straightforward like FTP, only difference is in SSL encryption. wodFtpDLX.NET supports two types of this protocol - FTPSwithdata, and FTPSnodata. As the name says - FTPSwithdata will also encrypt data connection which is used to transfer files (and directory listings), while FTPSnodata does not encrypt secondary connection. You should use FTPSnodata if you don't care about encrypting files (only want to protect your username and password, for example) because it is much faster than the other one.

There is also FTPSimplicit protocol that is same as above, but will negotiate SSL before any commands are sent to the server. It is widely used by 3rd party wrapper software that actually translate between SSL encrypted connections and older FTP servers that wouldn't support SSL. Typical port is 990 for this protocol.

SFTP is completelly different protocol who has only one thing incommon to above protocols - file transfer. Everything else is different. It is packet-oriented, running on top of SSH2 (secure shell) and thus requires different server to be installed (SSH2 with SFTP subsystem). It uses only one connection (no separate data connection), and it doesn't have text replies like FTP used to have. Encryption and protection for this protocol is already guaranteed by SSH layer.

Platforms

Windows