Virtual Hosting is a process in which we can host multiple sites on a single server. or we can also say single Apache to have multiple sites.

Types of Virtual Hosting

Virtual hosting is of two types-
1. Name Based
2. IP Based

Name Based Virtual Hosting

In Name Based virtual hosting the host name is provided by the client, so many host names points to a single IP address For Example: There could be two domains
1- www.firstexample.com
2- www.secondexample.com
Both the above domains are mapped to the same IP address say "111.1.110.28".

Steps to create virtual hosts for Debian based Linux distributions

Step 1: First check for a default virtual host file on the below mentioned path

/etc/apache2/sites-enabled/000-default.conf

copy and paste 000-default.conf file for the number of domain names you want to create, (in our case we have two domains). Rename these file, as per Ubuntu file name should end with suffix ".conf"

sudo cp /etc/apache2/sites-available/000-default.conf /etc/apache2/sites-available/firstexample.com.conf

sudo cp /etc/apache2/sites-available/000-default.conf /etc/apache2/sites-available/secondexample.com.conf

Now open the file in any editor

sudo nano /etc/apache2/sites-available/firstexample.com.conf

we configure the virtual host file as below

Note: request are taken on port 80 by default, we can also change this port to another for this make sure no other porcess is using this port.

Listen 80
<VirtualHost *:80>
    ServerAdmin admin@firstexample.com (This will help server admin receive email on admin@firstexample.com)
    ServerName firstexample.com
    ServerAlias www.example.com
    DocumentRoot /var/www/firstexample/public&#95;html
    # Other directives here
</VirtualHost>

Similarly for secondexample.com

sudo nano /etc/apache2/sites-available/secondexample.com.conf

<VirtualHost *:80>
    ServerAdmin admin@secondexample.com (This will help server admin receive email on admin@secondexample.com)
    ServerName secondexample.com
    ServerAlias www.example.com
    DocumentRoot /var/www/secondexample/public&#95;html

    # Other directives here
</VirtualHost>

Step 2: Now enable the above virtual files

sudo a2ensite firstexample.conf
sudo a2ensite secondexample.conf

Steps to create virtual hosts for CentOS based Linux distributions

Step1: Now check for a default virtual host file on the below mentioned path

/etc/httpd/conf

create the /etc/httpd/conf/vhosts directory
a.) cd /etc/httpd/conf
b.) mkdir vhosts

Creating a virtual host conf file firstexample.com.80.conf under directory vhosts

c.) cd vhosts
d.) cat > firstexample.com.80.conf (creating file).
e.) nano firstexample.com.80.conf (open firstexample.com.80.conf in terminal base editor nano).

Step2: Now type the following lines in your virtual host file firstexample.com.80.conf

Listen 80
<VirtualHost 111.1.110.28:80>
    ServerAdmin admin@ firstexample.com
    ServerName  firstexample.com
    ServerAlias www. firstexample.com
    DocumentRoot /www/firstexample.com/html

    # other directives
</VirtualHost

Save your changes (CTRL-O) and exit nano (CTRL-X).

Steps to follow for Debian and CentOS based operating system

the below steps have to follow for Debian and CentOS based operating system once when step 1 and step 2 are done.

---> Restart apache2

----> For testing the virtual host on our local machine, open a "host" file on below mentioned path

----> sudo nano /etc/hosts

----> add the following lines in file

127.0.0.1   localhost<br>
111.1.110.28 firstexample.com<br>
111.1.110.28 secondexample.com<br>

This directs any request for firstexample.com and secondexample.com from the clients computer and send the requests to the server at 111.1.110.28. Save the changes.

IP Based Virtual Hosting

In IP Based virtual hosting each host name is mapped to a unique IP address.

Therefore for virtual hosting here you have to make changes in 000-default.conf as below and rename the file with adding ".conf" to the name.

Listen 80
<VirtualHost 111.1.110.28>
    ServerAdmin admin@firstexample.com (This will help server admin receive email on admin@firstexample.com)
    ServerName firstexample.com
    ServerAlias www.example.com
    DocumentRoot /www/firstexample
</VirtualHost>


<VirtualHost 111.1.110.82>
    ServerAdmin admin@secondexample.com (This will help server admin receive email on admin@secondexample.com)
    ServerName secondexample.com
    ServerAlias www.secondexample.com    
    DocumentRoot /www/secondexample
</VirtualHost>