Passive Mode FTP Through Proxy Server

• Microsoft Proxy Server versions 1.0 and 2.0

SUMMARY

When you use passive mode FTP, the FTP server negotiates a secondary Dynamic port for all subsequent transmissions with the FTP client. This article describes how to set up this process to work with Microsoft Proxy Server.

MORE INFORMATION

NOTE: Proxy Server version 2.0 allows passive mode FTP by default.

Passive mode FTP allows the FTP server to negotiate with the client to communicate over a port other than 21. This frees up port 21 for a new connection to be made, and eases traffic on the primary port. The server picks a new port (usually between 1025 and 5000), and then the client communicates with the server on that new port.

To configure the Proxy Server in this manner, perform the following steps:

1. Open the properties for the WinSock Proxy in Internet Service Manager.

2. Click the Protocols tab.

3. Open the properties for the FTP protocol.

4. Click Add.

5. Add a range of ports from 1025 to 5000, and set the type as TCP and the direction as outbound.

6. Apply the changes and stop and restart the WinSock proxy server.