Connection Page (Advanced Site Settings dialog)

The Connection page on the Advanced Site Settings dialog allows you to configure general protocol-independent options for the connection.

More connection options are available on subpages:

Proxy (connection through proxy server)
Tunnel (connection through SSH tunnel)
TLS/SSL (TLS/SSL protocol options)

Refer to documentation of page sections:

Connection
Timeouts
Internet Protocol Version
Further Reading

Connection

Use Passive mode to toggle between passive and active FTP connection mode. Passive mode is selected by default. The option is supported only with FTP protocol.

The Optimize connection buffer size enables optimization of socket buffer size. It greatly improves transfer speed. Disable it only when experiencing problems. The option is not available with WebDAV and S3 protocols.

Timeouts

By the Server response timeout you define how long should WinSCP wait for an answer from the server before displaying window with option to Abort the connection. Note that the window does not block the waiting, so when it is displayed and the response is finally received it disappears itself.

WinSCP can automatically reconnect session, if the server is not responding too long.

Internet Protocol Version

This option allows the user to select between the old and new Internet protocols and addressing schemes (IPv4 and IPv6). The default setting is Auto, which means WinSCP will do something sensible and try to guess which protocol you wanted. (If you specify a literal Internet address, it will use whichever protocol that address implies. If you provide a hostname, it will see what kinds of address exist for that hostname; it will use IPv6 if there is an IPv6 address available, and fall back to IPv4 if not.)

If you need to force WinSCP to use a particular protocol, you can explicitly set this to IPv4 or IPv6.1

The option is not available with WebDAV and S3 protocols.