cita310chap09
DESCRIPTION
TRANSCRIPT
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Web Server Administration
Chapter 9Extending the Web
Environment
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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
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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
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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
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Communicating with FTPCommand 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 FTPCommand 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 FTPCommand 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
Windows component Part of IIS
Configured through Internet Information Services (IIS) Manager
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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
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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
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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
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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
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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
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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
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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
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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"
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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
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Common net CommandsCommand 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 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 permissionsPermissions 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 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
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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
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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
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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
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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 Highly customizable
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Summary 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