What is an Extranet
Extranet is a communication tool designed to enable easy information sharing within the workgroups. Extranet is basically a computer network that allows controlled access from the outside for specific business or educational purposes. It is actually an Intranet that is partially accessible to authorized outsiders.
Extranets are used much in the same way as intranet except the fact that they can be accessed remotely. Many organizations use the extranet as a way to exchange large files between the organization and an outside contractor. All the outside contractors would need a password, so that they can access the extranet from the Internet.
The extranet serves as an extended enterprise including a number of customers or suppliers but in a defined number. Companies often use extranets to provide nonpublic information to a select group of people. That’s why to access it, the user needs to enter a password or use some sort of digital encryption even though it looks ordinary.
The actual server that serves up the web pages will reside behind a firewall just as intranet usually is but the extranet is opened to a selected members or partners i.e. the firewall helps to control access between the Intranet and Internet permitting access to the Intranet only to people who are suitably authorized. There can be different levels of access depending upon the group of outside users who will be accessing the extranet. This access can be based on username and password or some unique ID or any other security measure. Extranet may apply to mixtures of open and closed networks.
Some examples of extranet applications are:
Private newsgroups that companies use to share valuable experiences and ideas. Groupware in which several companies collaborate in developing a new application program. Training programs or other educational material that companies develop and share and Shared product catalogs etc…
Extranets have to be carefully sealed before large organizations feel comfortable with them. Security is required at various levels. First, the company must control who it is letting into the extranet and second, the company needs to control its resources which can be accessed. Threats are also there to the system from malicious activities or persons as many of them searches for the company’s secrets. So this should also be considered while implementing extranet.