Introduction
In virtual hosting you can maintain more than one server on a single machine. You can have multiple domain names on a single or multiple servers. Server can share the resources like memory. It does not need all servers to use one and same host name. Shared Web Hosting is widely used and common virtual host application. They are cheaper as compared to web server because by using virtual hosting multiple clients can be hosted on one server.
History
If any business wants to provide low cost web hosting then virtual hosting is used there. Shared servers are used mostly in virtual hosting. If there are some internal processes of any organization then they use virtual servers; if they want to have different intranet or extra-net websites due to some technological reasons. To reduce the administrative and management overhead these web sites can be combined.
Features
There are two types of virtual hosting as following:
- Name based
- IP based
Name Based:
This virtual hosting uses the name of the host which is given by the customer by saving IP addresses. You can have same IP address for many hosts. There may be some problems in using name-based virtual hosting machines with SSL/TLS. There is a problem in name based virtual hosting which is; you can face difficulty to host many websites which run SSL/TLS. Before the host name is sent to the server; the handshake of SSL/TLS takes place. But there comes a problem; that which certificate should be shown during handshake. Single certificate can cover many names of host. You can either use subject-alt-name or wild-cards. Server Name Indication is an extension to the TLS. It shows the name at the beginning of shaking hand. To access the virtually hosted website Domain Name System (DNS) should properly work. Web server totally relies on the browser that’s why there should be DNS in running mode. Only IP address is not enough.
IP Based:
Each host name has a specific and different IP address. There is a proper IP address for each domain name. There is a unique IP address in this case. There can be many physical interfaces or IP addresses on single interface. There is a problem in using IP-based virtual hosting; you need a separate IP address for each web site. Administrative overhead can be increased in this way. Apache is the first server which uses IP based virtual hosting. The version of Apache 1.1 and later supports IP based as well as Name based Virtual Hosting.
Name-based and IP-based both can be merged. There can be multiple IP addresses for a single server. If you want to use SSL/TSL along with wild card certificates then this combination is a good option.
Tips and comments
Port Based:
There is another virtual hosting machine known as Port Based Virtual Hosting which is rarely used. Most of the web servers don’t need any specific port number for configuration. There is a default port number for HTTP which is 80. It is not friendly to the end user. User does not know the port number of his website in this case; that’s why non-standard port number is being used.
