FTP Access via Proxy Server
By using a proxy server, access to Internet resources can be controlled and restricted. Access control can be based on access method, IP address, or domain name.
This means, for example, that the proxy site server only allows some special computers in the local area network to access the Internet in order to prevent unnecessary costs arising from improper or unintentional use of the Internet.
In addition, the WWW access behavior of the local users can be analyzed with the help of a proxy server at the Internet transition. The proxy records client transactions for this purpose.
An entry in a log file contains, for example, the IP address of the requesting client, date and time, the URL of the requested object, the size of the transmitted data in bytes and the status code of the HTTP transaction.
In addition to these advantages, the use of a proxy server on the firewall machine also has a major disadvantage.
Since the firewall is the only point of attack of the local network in relation to the Internet, as few security-related applications as possible should run on the firewall in order to minimize any potential security gaps.
Because the more extensive a software is, the more likely it is that it contains errors and thus security holes. For example, if the CERN server is used as a proxy server on the firewall machine, it represents a potential attack target from the outside.