Web Server Administration
Chapter 9
Extending the Web Environment
Overview
■ 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
Understanding FTP Services
■ 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
■
Also command-line and GUI clients
■ FTP servers can operate as anonymous servers or they can require a valid logon
■
Typically, they are anonymous
■
FTP servers are not secure; user names and
passwords are not sent encrypted
Understanding FTP Services
■ 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
Communicating with FTP
dir *.rpm Displays the long listing of files and
their properties, such as the size and date the file was created
dir
filenames
ls *.rpm Displays filenames and can use
wildcards ls
filenames
Closes the connection and exits the bye FTP client
quit or bye
close Closes the connection but does not
exit the FTP client close
open 192.168.0.100 Once the FTP client has been started,
opens a connection open host
ftp 192.168.0.100 Initiates a connection to FTP server
ftp host
Example Description
Command
Communicating with FTP
prompt Starts prompting
prompt
prompt no Stops prompting for each file
when used before you use mget or mput
prompt no
mput *.tif Uploads multiple files;
used with wildcards mput filenames
mget sendmail*.rpm Downloads multiple files;
used with wildcards Mget filenames
put testapp.zip Uploads a single file
put filename
get test.rpm Downloads a single file
get filename
ascii Transfer files in text mode
ascii
binary Transfer files in binary mode
binary
Example Description
Command
Communicating with FTP
help mget 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 command
Displays the current directory on pwd the server
pwd
lcd /docs Moves to another directory on the
client lcd directory
cd /software Moves to another directory on the
FTP server cd directory
Displays a hash symbol as files hash are being downloaded
hash
Example Description
Command
Install and Configure Windows FTP Server
■ Windows component
■
Part of IIS
■ Configured
through Internet Information
Services (IIS)
Manager
Configure FTP Messages
■
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
Install FTP in Linux
■ The wu-ftpd FTP server was developed by Washington University
■ Once the rpm is installed, enable FTP
■ chkconfig wu-ftpd on
■ Restart xinetd service to recognize change
■
service xinetd restart
Configure /etc/ftpaccess
■ The /etc/ftpaccess file is the main configuration file
■ By default, users with IDs less than or equal to 99 are not allowed
■ They are for system users and daemons
■ Because the ftp user is a system user, you have to allow it with
■
allow-uid ftp
■
allow-gid ftp
Configure /etc/ftpaccess
■ Limit user to a maximum of five failed logons before a disconnect
■ loginfails 5
■ Check for password that conforms to e-mail address
■ passwd-check rfc822 warn
Control Access
■ Set up user classes
■ class all real,guest,anonymous *
■ class local real 192.168.0.0/24
■ Set limits for class
■ file-limit out 25 anonymous
■ file-limit in 10 local
■ byte-limit out 2000000 anonymous
Configure Messages
■
To receive notice that a readme file exists at login or any current working directory (cwd)
■
readme README* login
■
readme README* cwd=*
■
To display a message when a user logs on or moves to a directory
■
message /welcome.msg login
■
message .message cwd=*
■
To create a banner message when client connects
■
banner /etc/banner.txt
Understanding News Servers
■ 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
Configuring Telnet in Linux
■
By default, telnet is installed but not enabled
■
chkconfig telnet on
■
service xinetd restart
■
Telnet should not be used in a non-secure
environment such as over the Internet because user names and passwords are not encrypted
■
ssh is a secure replacement (described in Chapter 10)
■
You cannot log on as root
■
However, you can log on as another user and "su root"
Telnet and Windows
■ Telnet is not popular in Windows because telnet is text-based and Windows relies on a GUI
■
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
Common net Commands
net use g: \\web1\docs Maps a drive
net use drive:
\\computer\share
net share docs=c:\docs Shares a folder
net share name=location
net start "FTP Publishing Service"
Starts a service net start service
net user mnoia Displays user
information net user username
net user Lists all users
net user
Example Description
Command
cacls options
■ The format is: cacls file or folder name [options]
As above, except permissions are replaced /p user:perm
Grants a user specific permissions Permissions are:
f (full control) r (read)
w (write) c (change) n (none) /g user:perm
Changes all subfolders /t
Changes instead of replaces permission /e
Description
Option
netsh Examples
■ Create a text file with commands to re-create the IP configuration
■
netsh interface ip dump
■ Ping the gateway IP address of each NIC
■
netsh diag ping gateway
■ In Windows Server 2003
■
Display errors in system log
■
Manage network monitor and performance
■
Defragment a drive
■
Shut down a server
Terminal Services in Windows
■ GUI-based access to a server
■ Can be used for remote administration or running applications remotely
■
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
Understanding Streaming Media Services
■ Used to transfer video and audio
■ By default, UDP is used
■
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
■
unicast – each packet is sent individually to each client
■
multicast – each packet is sent to many clients
Understanding Streaming Media Services
■ Helix Universal Server from Real Networks is popular
■ Recognizes both Real Networks protocols (RTSP, PNA) and the Microsoft protocol (MMS)
■ Windows Media Services is a Windows component
■ Creates a folder called \ASFRoot to store
Advanced Streaming Format (ASF) files
Understanding E-Commerce Servers
■ 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
■
Incorporates a number of features required for a typical e-commerce site
■
