Despite the advances in the original FTP protocol there are still some problems that remain unsolved. These problems have less to do with the protocol and more to do with supporting users of the protocol. For this reason these issues cannot be easily solved at the protocol level.

Firewalls

As companies become more concerned about network security, firewalls have become a commonplace appliance. Unfortunately while these firewalls can prevent unauthorized users from getting onto the network they can also inadvertently prevent legitimate users from accessing company resources. To resolve this issue a network administrator must typically modify the firewall rules for each user and their corresponding outbound and inbound FTP connections. Aside from making it more difficult for users to connect, managing this process can also be costly and error prone.

Client Support

There are a vast number of FTP clients available today, each with it's own set of features and also their own interpretation of the FTP protocol specifications. FTP server administrators must know how to support all of these different clients as well as know which ones are compatible with their particular FTP server. There is also the additional cost of purchasing FTP client licenses for each user and the maintenance of these licenses over time.
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