Additional Introductory Topics
The last few topics of this chapter may not appear to be directly related to networking, but they cover Linux help methods that you'll use extensively and the File Transfer Protocol (FTP) package, which enables you to download all the software you need to get your Linux server operational as quickly as possible.
The File Transfer Protocol
FTP is one of the most popular applications used to copy files between computers via a network connection. Knowledge of FTP is especially important and is a primary method of downloading software for Linux systems.
There are a number of commercially available GUI-based clients you can load on your PC to do this, such as WSFTP and CuteFTP. You can also use FTP from the command line, as shown in Chapter 5, "Troubleshooting Linux with Syslog," on RPM software installation.
From the remote user's perspective, there are two types of FTP. The first is regular FTP, which is used primarily to allow specific users to download files to their systems. The remote FTP server prompts you for a specific username and password to gain access to the data.
The second method, anonymous FTP, is used primarily to allow any remote user to download files to their systems. The remote FTP server prompts you for a username, at which point the user types anonymous or ftp with the password being any valid e-mail address.
From the systems administrator's perspective, there are two more categories. These are active and passive FTP, which are covered in more detail in Chapter 15, "Linux FTP Server Setup."
Remember that FTP isn't very secure because usernames, passwords, and data are sent across the network unencrypted. More secure formssuch as SFTP (Secure FTP) and SCP (Secure Copy)are available as a part of the Secure Shell package (covered in Chapter 17, "Secure Remote Logins and File Copying") that is normally installed by default with Fedora.
Linux Help
Linux help files are accessed using the man or manual pages. From the command line you issue the man command followed by the Linux command or file about which you want information. If you want to get information on the ssh command, you use the command man ssh:
[root@bigboy tmp]# man ssh
If you want to search all the man pages for a keyword, use the man command with the -k switchfor example, man -k ssh, which gives a list of all the man pages that contain the word ssh:
[root@bigboy tmp]# man -k ssh
...
...
ssh (1) - OpenSSH SSH client (remote login program)
ssh [slogin] (1) - OpenSSH SSH client (remote login program)
ssh-agent (1) - authentication agent
ssh-keyscan (1) - gather ssh public keys
ssh_config (5) - OpenSSH SSH client configuration files
sshd (8) - OpenSSH SSH daemon
sshd_config (5) - OpenSSH SSH daemon configuration file
...
...
[root@bigboy tmp]#
This book is targeted at proficient Linux beginners and above, so I'll be using a wide variety of commands in this book without detailed explanations to help keep the flow brisk. If you need more help on a command, use its man page to get more details on what it does and the syntax it needs. Linux help can sometimes be cryptic, but with a little practice the man pages can become your friend.
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