Book Image

Understanding TCP/IP

By : CP Books a.s.
Book Image

Understanding TCP/IP

By: CP Books a.s.

Overview of this book

This book covers in detail the Open System Interconnection (OSI) reference model and the TCP/IP protocols that operate that different layers. Its coverage includes various application protocols. The authors explain in an easy-to-read style networking concepts and protocols, with examples that make the book a practical guide in addition to its coverage of theory.
Table of Contents (20 chapters)
19
Index

13.2 Active Mode of FTP Protocol Communication

Active mode is the basic mode of FTP protocol communication. The most frequently asked question is how the user can influence the option of the communication mode. The answer is hard to give because an FTP client developer must enable this option. Only some clients have such an option; Linux clients support the proxy command, but Windows clients doesn’t support the proxy command. On the other hand, most Internet browsers use passive mode. However, servers usually support both communication modes.

At first, we will briefly show a scenario of active communication in the following table:

Step

FTP communication

1.

C:\WINDOWS\system32>ftp ftp.ripe.net

Connected to hawk-ftp.ripe.net.

220 FTPD Server (RIPE NCC FTP server)

2.

User (hawk-ftp.ripe.net:(none)): anonymous

331 Anonymous login ok, send your complete email address as your password.

3.

Password:

4.

230-Welcome 194.149.105.131,

230-

230-This is the ftp-server...