Security

You can generally divide security in two aspects. One is security when it comes to stable operation and availability, which means how your resources are accessible. The other aspect is how secure are your data from insight and manipulation of information.

When it comes to the first one, it depends on how you design and build your network. A common way to view the design is the "top-down" method. The top management define the demands and then you are going down in the hierarchy and in the end technicians put the chosen equipment and configurations together. Too often it is built the other way, technicians put something together without knowing the actual demands from the company and production.

The second aspect is primarily two parts, The first is that when you receive something you can be assured that is what was sent in the other end. The second is that the data transferred over the network is not visible for unauthorized persons.

To guarantee the senders identity so called certificates which contain keys for encryption is used. To guarantee integrity a control number (hash) is generated and sent with the data.

Whit in the IP technology different methods have developed to solve the different security demands. With the support of those methods has standardized systems emerged to encrypt information and distribute keys as well as guarantee the identity of the sender of information. The most common method today is called IP-sec and is used for setting up secure connections over the Internet