Web Server Administration
Chapter 9
Extending the Web Environment
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Overview
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Understand File Transfer Protocol (FTP)
services
Install and configure an FTP server in
Windows
Install and configure an FTP server in Linux
Understand News servers
Configure remote access to a server
Understand streaming media servers
Understand e-commerce software
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Understanding FTP Services
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FTP is used to transfer files from a server to a
client (download) and transfer files from a
client to a server (upload)
FTP client is the browser
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Also command-line and GUI clients
FTP servers can operate as anonymous
servers or they can require a valid logon
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Typically, they are anonymous
FTP servers are not secure; user names and
passwords are not sent encrypted
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Understanding FTP Services
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The client connects to port 21 (control
port)
Port 20 (data port) is used to tell the
client which unprivileged port to use for
data transfer
The above describes passive mode FTP,
the most common type
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Communicating with FTP
Command
Description
Example
ftp host
Initiates a connection to FTP server
ftp 192.168.0.100
open host
Once the FTP client has been started,
opens a connection
open 192.168.0.100
close
Closes the connection but does not
exit the FTP client
close
quit or
bye
Closes the connection and exits the
FTP client
bye
ls
filenames
Displays filenames and can use
wildcards
ls *.rpm
dir
filenames
Displays the long listing of files and
their properties, such as the size and
date the file was created
dir *.rpm
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Communicating with FTP
Command
Description
Example
binary
Transfer files in binary mode
binary
ascii
Transfer files in text mode
ascii
get filename
Downloads a single file
get test.rpm
put filename
Uploads a single file
put testapp.zip
Mget filenames Downloads multiple files;
used with wildcards
mget sendmail*.rpm
mput filenames Uploads multiple files;
used with wildcards
mput *.tif
prompt no
Stops prompting for each file
when used before you use
mget or mput
prompt no
prompt
Starts prompting
prompt
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Communicating with FTP
Command
Description
Example
hash
Displays a hash symbol as files
are being downloaded
hash
cd directory
Moves to another directory on
the FTP server
cd /software
lcd directory
Moves to another directory on
the client
lcd /docs
pwd
Displays the current directory on
the server
pwd
help command
Finds very brief help on FTP
commands; if used without a
reference to a command, it
will give you a list of
commands available
help mget
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Install and Configure Windows
FTP Server
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Windows
component
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Part of IIS
Configured
through Internet
Information
Services (IIS)
Manager
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Configure FTP Messages
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Banner appears when
client connects
Welcome appears
when logged on
Exit appears when
client exits from
server
Maximum connections
appears when limit is
reached and client
cannot connect
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Install FTP in Linux
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The wu-ftpd FTP server was developed
by Washington University
Once the rpm is installed, enable FTP
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chkconfig wu-ftpd on
Restart xinetd service to recognize change
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service xinetd restart
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Configure /etc/ftpaccess
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The /etc/ftpaccess file is the main
configuration file
By default, users with IDs less than or
equal to 99 are not allowed
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They are for system users and daemons
Because the ftp user is a system user, you
have to allow it with
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allow-uid ftp
allow-gid ftp
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Configure /etc/ftpaccess
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Limit user to a maximum of five failed
logons before a disconnect
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loginfails 5
Check for password that conforms to email address
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passwd-check rfc822 warn
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Control Access
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Set up user classes
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class all real,guest,anonymous *
class local real 192.168.0.0/24
Set limits for class
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file-limit out 25 anonymous
file-limit in 10 local
byte-limit out 2000000 anonymous
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Configure Messages
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To receive notice that a readme file exists at login or
any current working directory (cwd)
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To display a message when a user logs on or moves
to a directory
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readme README* login
readme README* cwd=*
message /welcome.msg login
message .message cwd=*
To create a banner message when client connects
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banner /etc/banner.txt
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Understanding News Servers
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News servers allow threaded discussions
You post messages in a newsgroup
A newsgroup focuses on a single topic
There are more than 40,000 public
newsgroups
There are hundreds of gigabytes of
information generated per day
News servers can be set up for use within an
organization
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Configuring Telnet in Linux
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By default, telnet is installed but not enabled
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Telnet should not be used in a non-secure
environment such as over the Internet because user
names and passwords are not encrypted
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chkconfig telnet on
service xinetd restart
ssh is a secure replacement (described in Chapter 10)
You cannot log on as root
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However, you can log on as another user and "su root"
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Telnet and Windows
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Telnet is not popular in Windows because telnet
is text-based and Windows relies on a GUI
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However, there are many command-line utilities that
can be used, especially in Windows Server 2003
Before Windows, Microsoft networking
depended on a single command net with many
options
cacls can be used to alter permissions
netsh starts a networking shell which allows you
to configure and display many network-related
items
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Common net Commands
Command
Description
Example
net user
Lists all users
net user
net user username
Displays user
information
net user mnoia
net start service
Starts a service
net start "FTP Publishing
Service"
net share
name=location
Shares a folder
net share docs=c:\docs
net use drive:
\\computer\share
Maps a drive
net use g: \\web1\docs
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cacls options
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The format is: cacls file or folder name [options]
Option
Description
/e
Changes instead of replaces permission
/t
Changes all subfolders
/g user:perm
Grants a user specific permissions
Permissions are:
f (full control)
r (read)
w (write)
c (change)
n (none)
/p user:perm
As above, except permissions are replaced
/r user /e
Revokes permission
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netsh Examples
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Create a text file with commands to re-create
the IP configuration
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Ping the gateway IP address of each NIC
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netsh interface ip dump
netsh diag ping gateway
In Windows Server 2003
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Display errors in system log
Manage network monitor and performance
Defragment a drive
Shut down a server
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Terminal Services in Windows
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GUI-based access to a server
Can be used for remote administration or
running applications remotely
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In Windows 2000, you select remote
administration on installation
In Windows Server 2003, it is installed already and
you have to enable it
Client software is included in Windows Server
2003 and Windows XP
You have to install client software for
Windows 2000
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Understanding Streaming
Media Services
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Used to transfer video and audio
By default, UDP is used
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Although TCP and HTTP can be used because of
firewall issues in an organization
No single standard exists as is true with
SMTP, HTTP, POP3, and others
Broadcast methods
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unicast – each packet is sent individually to each
client
multicast – each packet is sent to many clients
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Understanding Streaming
Media Services
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Helix Universal Server from Real
Networks is popular
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Recognizes both Real Networks protocols
(RTSP, PNA) and the Microsoft protocol
(MMS)
Windows Media Services is a Windows
component
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Creates a folder called \ASFRoot to store
Advanced Streaming Format (ASF) files
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Understanding E-Commerce
Servers
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Can be as simple as a product list and a
shopping cart
Can be as complex as amazon.com or
dell.com
Microsoft Commerce Server is an add-on to
IIS
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Incorporates a number of features required for a
typical e-commerce site
Highly customizable
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Summary
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Use FTP to transfer files
You use News servers to set up threaded
discussions on a variety of topics
Telnet and Windows Terminal Services allow
you to remotely administer a server
Streaming media servers are used for video
and audio
E-commerce servers focus on selling and in
general, communicating with customers
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