Configuring the Wu-FTPd Server

Wu-FTP uses a number of configuration files to control how it operates, including the following:

• ftpaccess Contains the majority of server configuration settings

• ftpconversions Contains definitions of file conversions during transfers

• ftphosts Settings to control user access from specific hosts

These files may be created in the /etc directory during RPM installation, or may be created by a system administrator. The following sections describe each of these files and how to use the commands they contain to configure the Wu-FTP server is accessible to all incoming requests.

CAUTION

When configuring an anonymous FTP server, it is extremely important to ensure that all security precautions are taken to prevent malicious users from gaining privileged level access to the server. Although this chapter shows you how to configure your FTP server for secure use, all machines connected to the Internet are potential targets for malicious attacks. Vulnerable systems can be a source of potential liability, especially if anyone accesses and uses them to store illegal copies of proprietary software even temporarily. There is little value in configuring a secure FTP server if the rest of the system is still vulnerable to attack. Use Red Hat's lokkit or system-config-securitylevel client to implement a firewall on your system.

TIP

Whenever editing the FTP server files, make a backup file first. Also, it is always a good idea to comment out (using a pound sign at the beginning of a line) what is changed instead of deleting or overwriting entries. Follow these comments with a brief description why the change was made. This leaves a nice audit trail of what was done, by whom, when, and why. If you have any problems with the configuration, these comments and details will help you troubleshoot and return to valid entries if necessary. You can use the rpm command or other Linux tools (such as mc) to extract a fresh copy of a configuration file from the software's RPM archive. Be aware, however, that the extracted version will replace the current version and overwrite your configuration changes.

NOTE

Back up the FTP server configuration files to another machine, should any of the working copies become corrupt. There might be a need to replicate server configurations across multiple hosts or revert back to an original copy of the defaults at some point in time. By making regular backups before changing a file, you guarantee that the changes can be undone and a working server restored with minimal down time.