Tutorial for setting up a VPN on Ubuntu Linux
A virtual private network, free vpn for linux , or VPN stands for Virtual Private Network, is a network technology that allows an extension of the local network over a public network or uncontrolled.
Common examples are the ability to connect two or more branches of a company using the Internet as a link, allowing team members support the connection from your home to the computer center, or a user can access from your home computer remote site, such as a hotel. All using the Internet infrastructure.
Virtual Private Networks using special security protocols that allow access to private services, only authorized personnel of enterprises, training centers, organizations, etc., When a user connects to the Internet, the network configuration VPN allows you to connect to the private network of the body with which to collaborate and access the same resources as if you were sitting quietly in his office.
What is a VPN?
A VPN is a corporate network structure implemented on a network of public resources, but it uses the same management and the same access policies that are used in private networks, the final analysis is nothing more than the creation in a public network environment of confidentiality and privacy that allow the user to work as if on the same local network. In most cases the public network is the Internet, but may also be an ATM or Frame Relay network
How a VPN
The communication between the two ends of the private network through the public network is done by setting virtual tunnels between these two points and using encryption and authentication systems which ensure the confidentiality and integrity of data transmitted through the public network. Due to the use of these public network, usually the Internet, it is necessary to pay special attention to the issues of security to prevent unauthorized access.
The tunneling technology (Tunneling) is a way of sending data which encapsulates a type of data packets within the data packet itself of any communications protocol, and upon reaching his destination, the original package is unpacked back and to their original state.
In the transfer over the Internet, packets is encrypted, for this reason, authentication techniques are essential for the correct operation of VPNs as to ensure that the transmitter and receiver are exchanging information with the user or correct device.
The virtual network authentication system is similar to login via username and password, but you have a greater assurance needs identity validation.
Most authentication systems are used in VPN system based on shared keys.
Authentication is typically done at the start of a session, and then, randomly, during the course of the session, to ensure there is no any third participant that has been intrude on the conversation.
All VPNs use some form of encryption technology that packages data into a secure package to be sent over the public network.
The encryption must be considered as essential as authentication, allowing secure data transported be visible and understood on the trip from one end to another connection.
There are two types of encryption techniques used in VPNs: secret key encryption, or private and public key encryption.
In secret key encryption uses a secret password known to all participants that they will make use of the encrypted information. The password is used for both encryption and decryption information. This type of system has the problem that, to be shared by all participants and must be kept secret, to be revealed, has to be changed and distributed to participants, which can create security issues.
The public key encryption involves the use of two keys, one public and one secret. The first is sent to the other participants. When encrypting, using own private key and the public key of the other participant in the conversation. Upon receiving the information, it is decrypted using its own private key and public information generator. The great disadvantage of this type of encryption is that it is slower than the secret key.
In the virtual network, the encryption should be done in real time, thus encrypted information flows across a network using encryption are secret key keys that are valid for the currently used session.