When you connect to a VPN, a “tunnel” is created between your device and the VPN server. All of your internet traffic is routed through this tunnel, so your data is secure from prying eyes. But how does this tunneling process work?
Checkout this video:
Introduction to VPN Tunneling
A Virtual Private Network (VPN) is a way of using a public telecommunication network, such as the Internet, to provide private resources and user access. A VPN can connect multiple sites, over either private or public networks. The encryption of communications between VPN sites provides security and protection against eavesdropping.
Tunneling is a process of encapsulating data within another data packet. In the context of a VPN connection, tunneling allows private network traffic to be transmitted over a public network, such as the Internet.
There are two types of tunneling: layer 2 tunneling protocol (L2TP) and point-to-point tunneling protocol (PPTP). L2TP is more secure than PPTP, but both protocols provide similar functionality.
In order to set up a VPN connection, you will need to have access to a VPN server. Many VPN providers offer both L2TP and PPTP access to their servers. Once you have access to a server, you can use either L2TP or PPTP to connect to it.
L2TP uses UDP port 1701, while PPTP uses TCP port 1723. To connect to a VPN server using L2TP, you will need to use an L2TP client software program. There are many different L2TP client programs available, both free and paid. Once you have installed and configured an L2TP client program on your computer, you can use it to connect to an L2TP-enabled VPN server.
To connect to a VPN server using PPTP, you will need to use a PPTP client software program. There are many different PPTP client programs available, both free and paid. Once you have installed and configured a PPTP client program on your computer, you can use it to connect to a PPTP-enabled VPN server.
How Tunneling Is Accomplished in a VPN
Tunneling is a process of encapsulating data within another data packet. When you tunnel data, you add an extra layer of protection because the data is less likely to be tampered with or intercepted. VPNs use tunneling to protect your data as it travels across the internet.
Layer 2 Tunneling Protocol (L2TP)
Layer 2 Tunneling Protocol (L2TP) is a tunneling protocol used to support virtual private networks (VPNs) or as part of the delivery of services by ISPs. It does not provide any encryption or confidentiality by itself. Rather, it relies on an encryption protocol that it passes within the tunnel to provide privacy.
L2TP was first published in 1999 as an enhancement to PPTP. In 2005, the L2TP over IPsec standard was published by the Internet Engineering Task Force (IETF). Today, L2TP is considered more secure than PPTP because it uses stronger encryption algorithms and offers additional security features.
L2TP is typically used with the IPsec protocol to protect data transmissions over public networks such as the Internet. When used in this way, L2TP is often referred to as L2TP/IPsec (layer 2 tunneling protocol/internet protocol security).
To set up an L2TP/IPsec VPN, you will need the following:
-A router that supports L2TP/IPsec connections
-A computer or mobile device with an operating system that supports L2TP/IPsec
-An Internet connection
-The IP addresses of the VPN server and your computer or mobile device
-The preshared key for your router (this is usually provided by your ISP)
Point-to-Point Tunneling Protocol (PPTP)
Point-to-Point Tunneling Protocol (PPTP) is a method for implementing virtual private networks. PPTP uses a control channel over an IP network, as well as GRE (Generic Routing Encapsulation) to encapsulate PPP frames. PPTP has been implemented on a variety of platforms, including Windows, Linux, and iOS.
When using PPTP, a VPN client first establishes a connection to a VPN server. The VPN client then authenticates with the server and negotiates a security policy. After the security policy is negotiated, the VPN client and server use GRE to encapsulate and send data packets. Data packets that are sent over the IP network are encapsulated with a GRE header and trailer.
GRE is a tunneling protocol that can encapsulate a variety of protocols, including IP, inside of it. When using GRE, each data packet is assigned a sequence number. The VPN client or server can use this sequence number to reassemble data packets that have been split into multiple pieces.
The use of GRE allows PPTP to tunnel other protocols besides IP, such as AppleTalk orIPX/SPX . In addition, GRE can be used to tunnel multicast traffic .
Secure Socket Tunneling Protocol (SSTP)
SSTP uses a SSL/TLS connection which offers a higher level of security by encrypting all traffic going through the tunnel. To prevent tampering and ensure that only authorized users can access the network, SSTP uses both server and client authentication. This two-way authentication process ensures that only authorized users can gain access to the network and that data passing through the tunnel is not tampered with.
To set up an SSTP connection, the user first needs to obtain a SSL/TLS certificate from a trusted Certificate Authority (CA). The user then needs to install the certificate on both the client and server machines. Once the certificate is installed, the user can configure the VPN software to use SSTP as the tunneling protocol.
SSTP is only available on Windows Vista SP1 and later or Windows Server 2008 and later.
Internet Protocol Security (IPsec)
Internet Protocol security (IPsec) is a secure method of data transmittal that uses encryption and other security measures to preserve the confidentiality, integrity, and authenticity of data in transit. IPsec is often used in Virtual Private Networks (VPNs) to provide a secure connection between two or more networks, or between a network and an individual user.
Tunneling is the process of encapsulating data in one protocol so that it can be transmitted over another protocol. In tunneling, the original data packet is encapsulated in a new packet with a new header that contains instructions for how the packet should be routed. The receiving computer strips off the new header and forwards the original data packet to its destination according to the instructions in the original header.
Tunneling is a key component of IPsec because it allows data to be securely transmitted over public networks such as the Internet. Without tunneling, data would have to be sent in plain text, which would make it vulnerable to interception and tampering. By encapsulating data in an IPsec tunnel, businesses can create VPNs that allow employees to securely connect to their corporate network from anywhere in the world.
There are two main ways to accomplish tunneling with IPsec: Transport Mode and Tunnel Mode.
In Transport Mode, only the data payload is encrypted; the headers are left intact. This is typically used for communicating between two hosts, such as when an employee uses a VPN client to connect to their company’s network from their home computer.
In Tunnel Mode, both the data payload and headers are encrypted. This is typically used for creating site-to-site VPNs, where traffic from one network is routed through an encrypted tunnel to another network.
Conclusion
Tunneling is the process of establishing and maintaining a logical network connection (usually referred to as a “virtual” connection) between two physically separate networks. A VPN tunnel encrypts your data traffic, providing a secure connection between your device and the VPN server. Once your data reaches the VPN server, it decrypts the data and forwards it on to its destination.