Tip: For detailed documentation refer to the IntelliSense tips that appear when you call a given API method.

• AutoConnect() - Automatically discover working FTP connection settings and use those to connect to the server. This method will intelligently try certain combinations of connection settings until it finds a working combination. The connection types are tried in this order of preference.

• AutoDetect() - Automatically discover working FTP connection settings and return those connection profiles. This method will intelligently try certain combinations of connection settings until it finds a working combination, and it will return the first found combination or all found combinations. The connection types are tried in this order of preference.

Use this code:

FtpClient client = new FtpClient(hostname, username, password); // or set Host & Credentials
client.AutoConnect();

Use this code:

FtpClient client = new FtpClient(hostname, username, password); // or set Host & Credentials
var profiles = client.AutoDetect();

// if any profiles are found, print the code to the console
if (profiles.Count > 0){
	var code = profiles[0].ToCode();
	Console.WriteLine(code);
}

Once you find a working connection profile, use the generated code to quickly connect to your FTP server.

Auto connection attempts to find working connection settings in this order of preference:

Protocol Preference:

1. Explicit FTPS (TLS) - very common
2. Plaintext FTP - very common
3. Implicit FTPS (SSL) - outdated and very rare

FTPS Protocol Preference:

2. Tls12 | Tls11 - TLS 1.2 or TLS 1.1 (TLS 1.3 is not yet stable in .NET Framework)
3. Tls - TLS 1.0
4. Default - Undefined/weird behaviour

Data Connection Type Preference:

• For servers connected over IPV6, we use EPSV (enhanced passive)
• For servers connected over IPV4, we try PASV (passive) which has the widest support on FTP servers

Encoding Type Preference:

• UTF8 - We always use Unicode if it can be supported by the server

Auto connection automatically calculates the best values for the following properties in FtpClient:

1. Port (unless a non-standard port is specified before calling AutoConnect)
2. EncryptionMode
3. SslProtocols
4. DataConnectionType
5. Encoding