Configuring the WSM using Device Manager

FTP server load balancing

RFC 959 defines two connections for FTP--one for control information and another for data. Each connection is unique. Unless the client requests a change, the server always uses TCP port 21 (a well-known port) for control information, and TCP port 20 for data. FTP uses TCP for transport. After the initial three-way handshake, a connection is established. When the client requests any data information from the server, it will issue a PORT command (such as ls, dir, get, put, mget and mput) via the control port.

There are two modes of FTP operation, active and passive.

Active FTP	The FTP server initiates the data connection.
Passive FTP	The FTP client initiates the data connection. Because the client also initiates the connection to the control channel, the passive FTP mode does not pose a problem with firewalls and is the most common mode of operation.

FTP network topology has the following restrictions:

FTP uses both a control channel and a data channel; both channels need to be bound to the same real server.
The FTP server may initiate FTP data sessions.
Information exchanged on the control channel is used to determine the IP address and port for data connections between the FTP server and the FTP client.