PASV

PASV

Passive FTP mode. PASV is a means to get around a problem where a firewall will block FTP communications. A firewall protecting a client will allow outgoing connections but block incoming ones. The issue with FTP is that whilst the client initiates the initial connection the server then allocates the port to use for data requests - and this is then blocked by the firewall. which is then blocked. PASV allows the client to initiate both the command and data requests and because this is initiated by the client the client's firewall does not block it.

For more information see:

• http://slacksite.com/other/ftp.html - Extensive article covering active and passive ftp.