Web Server Administration


Dec 4, 2013 (4 years and 7 months ago)


Web Server Administration

Chapter 6

Configuring a Web Server


Understand how a Web server works

Install IIS and Apache Web servers

Examine the IIS and Apache properties

Host multiple Web sites

Configure new Web sites in IIS and

Understand virtual directories

How a Web Server Works

HTTP (Hypertext Transfer Protocol) defines
how information is passed between a browser
and a Web server

The two most popular Web servers are

Apache from Apache Software Foundation

Internet Information Services (IIS) from Microsoft

The original Web server from Microsoft available on
Windows NT was Internet Information Server

Almost two
thirds of all Web servers use

How a Web Server Works

As is true with other servers such as
DNS, Web servers listen for
communication at a port

The default port is 80

You can also create Web servers at port
numbers greater than 1023

Each Web server has a root, which is
where you store the HTML documents

Understanding HTTP

The current version of HTTP is 1.1

Virtually no browsers are so old that they
do not support 1.1

HTTP is a stateless protocol, meaning
that each Web page sent is
independent of every other Web page

This makes it more challenging to create a
shopping cart application

Understanding HTTP

HTTP 1.1 supports persistent

This allows the browser to receive multiple
files in one TCP connection

This can speed up communication

Although you see a single page in your
browser, it can be composed of many text
and image files

Understanding HTTP

When the browser sends a request to a Web
server, it looks like:

GET /hello.htm HTTP/1.1

Host: www.technowidgets.com

The above requests the hello.htm file from the
root of the Web server

It specifies the host of www.technowidgets.com

There could be multiple hosts at the IP address

Understanding HTTP

The following shows some of the headers
along with the HTML that the Web server
would send:

HTTP/1.1 200 OK

Server: Microsoft

Type: text/html

Modified: Fri, 17 May 2005 18:21:25 GMT

Length: 43


Hello, World


The headers contain information about the

Features in Apache

Apache 1.3 was used for many years but version 2.0
was released in 2001

Apache can also be used as a proxy server

A proxy server isolates your real Web server from the

Apache 2.0 has

Better support for Windows

Support for IPv6

Simplified configuration

Unicode support in Windows

Multilanguage error responses

Apache supports many programming languages such
as Perl and PHP

Features in IIS

IIS versions associated with Windows

Windows NT

IIS 4.0

Windows 2000

IIS 5.0

Windows Server 2003

IIS 6.0

SMTP can be easily added so you can
send e
mail from your Web pages

Features in IIS 5.0

Web Distributed Authoring and Versioning

Allows a server to share Web
based files

Named virtual hosting

Multiple Web sites can share a single IP address

Per Web site bandwidth throttling

Control bandwidth by Web site

Kerberos authentication

Secure Sockets Layer 3.0

Encrypted communication

Features in IIS 6.0

Increased security

Default permits only HTML documents

Expanded language support

Can use XML and SOAP

Support for IPv6

Increased dependability

mode HTTP service

healing mechanism

Components in IIS

File Transfer Protocol (FTP) server

To transfer files between user and server

FrontPage 2000 Server Extensions

Used by programs to transfer files to and from a
Web site

NNTP Service

Used to create user forums

SMTP Service

World Wide Web Server

Installing Apache

Apache can be installed when you install

It is also on Red Hat CD 2

If you install it from the Red Hat CD, the
directories will be consistent with other server

If you download it from the Apache Web site,
you have to compile it and install it

Starting Apache

By default, Apache does not start after you
install it

The following table has a list of commands



Start Apache

apachectl start

Stop Apache

apachectl stop

Restart Apache

apachectl restart

Minimal Apache Configuration

Add a ServerName in

Add apachectl start to /etc/rc.d/rc.local

Default Web Site Properties in

Tabs on the Default Web Site
Properties Dialog Box

Operators (Windows 2000) only

This property lists users who can administer Web


Limit bandwidth by Web site

Limit simultaneous connections (Windows 2003)

ISAPI Filters

Specify applications that process HTTP requests

Tabs on the Default Web Site
Properties Dialog Box

Home Directory

Specifies the location and properties of the root

Log information here



Configure the name for default Web pages

HTTP Headers

Add your own custom headers

Custom Errors

Create custom pages for HTTP errors

Apache Properties

Global Environment


Directory location of server files


Indicates whether Apache should maintain
a persistent connection


Determines the port number for the server

Default is 80

Apache Properties

Main Server Configuration


Shows the user name that Apache employs when
someone requests a Web page

The default is apache


mail address of administrator


DNS host name or IP address of server


Directory where the Web pages are stored

Hosting Multiple Web Sites

by Port Number

Associate each new Web site with a
port above 1023

To retrieve a Web page from a site at
port 8080


Because it requires a user to add the
port number, it is not a popular method

Hosting Multiple Web Sites

by IP Address

You can create multiple IP addresses on a
single NIC

Referred to as virtual IP addresses

Useful for flexibility because if each domain
has its own unique IP address, you can easily
move the domain to a different Web server

It is getting more expensive to get multiple IP
addresses from an ISP

Hosting Multiple Web Sites

by Host Name

Multiple host names can be associated
with a single IP address

Getting a single IP address from your ISP
is relatively inexpensive

You can host an almost unlimited number
of domains with a single IP address

It is the most common method of hosting

Configuring a Virtual Host Based
on an IP Address in Apache

In /etc/rc.d/rc.local, add an IP address
such as:

/bin/ifconfig eth0:0

In the Virtual Host section of httpd.conf


ServerName research.technowidgets.com

DocumentRoot /var/www/research


Configuring a Virtual Host Based
on a Host Name in Apache

NameVirtualHost defines the common IP address

Multiple configurations repeat the same IP address
and define unique ServerName settings



ServerName www.technowidgets.com

DocumentRoot /var/www/html



ServerName web1.technowidgets.com

DocumentRoot /var/www/web1


Configuring a Virtual Directory
in Apache

The following associates the virtual directory
called prod with the location of the directory

Alias /prod/ “/var/www/prod/”

Then it configures the directory

<Directory “/var/www/prod”>

AllowOverride None

Order allow, deny

Allow from all



Web servers use HTTP to send HTML

IIS is from Microsoft while Apache is
from Apache Software Foundation

IIS modifications are made through
property pages

Apache modifications are typically made
by changing /etc/httpd/conf/httpd.conf


You can create multiple Web sites on a
single computer by adding port
numbers, IP addresses, and/or host

Virtual directories are directories that
appear to be located beneath the root,
yet are physically located elsewhere