Updated April 1, 2023
Introduction to Virtual Private Network
There are two types of network public network and a private network. Public network is public telephone system and internet. It is a collection of communicators that are generally unrelated to each other. A private network is made up of computers that are owned by a single organization, which share the information with each other. For example, LAN (Local Area Networks), WAN (Wide Area Networks) and MAN (Metropolitan Area Networks) are examples of private networks. To separate private network from a public network, a firewall is used.
Suppose an organization has two branches one in New York and another in Ohio and wants to connect these two branches. It can be done in two ways. One is to connect two branches using a personal network like cables and another is to connect using a public network such as the internet. The first ways offer more security, but it is quite tough or complex to connect these two branches over cable. If we use the second option, then there are chances of malware attacks.
It is a mechanism that provides encryption, integrity protection, and authentication so that we can use the public network such as the internet as if it is a private network. It offers a high level of security and does not require any special cabling on behalf of the organization that wants to use it. In other words, we can say that this network combines the advantages of public networks with a private network.
It can connect a distant network of organizations or it can be used to allow traveling users to remotely access a private network over the internet in a secure manner. It is thus a mechanism that stimulates private networks over a public network such as the internet. the virtual word signifies that it depends on the use of virtual connections. These connections are temporary and do not have any physical appearance. They are made up of packets.
How does Virtual Private Network work?
Suppose an organization has two networks i.e. network 1 and network 2. These two networks are apart from each other. An organization wants to connect these two networks using a virtual private network. In this scenario, to connect two networks, two firewalls are used. Firewall 1 and Firewall 2. These firewalls perform the encryption and decryption process itself. Network 1 is connected to the internet with its own firewall 1. Similarly, network 2 connects to the internet with its own firewall 2. Here firewalls are virtually connected to each other over the internet.
Suppose, host A on network 1 wants to send a data packet to host B on network 2. The transmission of a data packet between this network is traveled as follows.
- First host A creates a packet and inserts its own IP address as the source address and the IP address of host B as the destination address. Then it sends the data packet using the appropriate mechanism.
- Data packet reaches firewall 1. Then firewall 1 adds the new headers to the packet. In these new headers, it changes the source IP address of the packet from that of host A to its own address. It also changes the destination IP address of the packet from that of host B to the IP address of firewall 2. It also performs encryption and authentication on packets depending on the settings. Then it sends the modified packet over the internet.
- Then packet reaches firewall 2 over the internet via routers. Firewall 2 then discards the outer header and performs decryption and encryption functions. This process results in the original packet that was created by host A in step 1 as we discussed above. Then it takes the content of the packet in plaintext form and realizes that the packet is meant for host B. Therefore it delivers the data packet to host B.
Protocols
1. PPTP: PPTP stands for point-to-point tunneling protocol which is used on WindowsNT systems. It supports the virtual private network connection between single-user and LAN. It does not support the virtual private network connection between LAN to LAN.
2. L2TP: L2TP stands for Layer 2 tunneling protocol is an improvement over PPTP protocol which is developed by IETF. L2TP consider a secure open standard for Virtual private network connections. It supports the virtual private network connection between single-user and LAN and LAN to LAN.
3. IPSec: It provides authentication and confidentiality service. It is used in isolation.
Conclusion
In this article we have seen what is Virtual Private networks, how does it work along with protocols used in VPN. We hope you will find this article helpful.
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