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What is VPN | How does VPN Work | VPN definition,VPN port

This page describes VPN definition or meaning.VPN full form is Virtual Private Network. The page covers how does VPN works and mentions why use VPN.It mentions VPN ports, advantages and disadvantages.

VPN definition:
The VPN is the short form of Virtual Private Network. It is a way to surf the internet anonymously amd securely. The VPN encrypt any data user is sending or receiving over public and less secure internet. Due to VPN no one can snoop in your activity over the internet.

what is VPN

VPN operates at layer-2 or layer-3 of the OSI model. There are three main types of VPN networks viz. Remote access VPN, Intranet VPN and Extranet VPN.

How does VPN Work

How does VPN Work

Following section describes how does VPN work.

From system perspective, VPN requires following in order to be operational and ready to provide the service.
• VPN router or VPN switch
• Software to create and manage tunnels
• Security device such as firewall
• Internet connection
• Existing hardware e,g. servers and work stations can be utilized.

As mentioned VPN utilizes layer-2 frame format i.e. ethernet and layer-3 frame format i.e. IP packet.

Tunneling in VPN allows senders to encapsulate their data in IP packets which hide the routing and switching infrastructure of internet. This will ensure data security against unwanted hackers or viewers.

From user perspective, it is very simple to use VPN. One need VPN program or application which resides on your computer, laptop, tablet or mobile. Once we have the VPN software or app, it need to be installed or to be turned ON. Next, user need to configure the VPN in the device. Once VPN is configured and it is ON, anything you do on internet is not accessible to the public.

• In summary, VPN works based on three components viz. protocols, security and appliances.
• It uses protocols such as IPSec (IP Security), PPTP (Point to Point Tunneling Protocol) and L2TP (Layer-2 Tunneling Protocol). Refer L2TP vs PPTP for more information.
• It uses encryption which scrambles the data to be transmitted and descrambles the encrypted data received in order to obtain plain text information. It uses keys of different sizes for scrambling/descrambling operation. It also uses user and system level authentication to provide security.
• It uses appliances such as firewall at packet and application to provide protection against intrusion.

VPN Ports

Following VPN ports are very useful. These VPN ports need to be open on firewall in order to allow VPN traffic to go through.
• IPsec utilizes IP protocol-50 for ESP. IP protocol-51 for AH, UDP port 500 and 4500 are used.
• SSL utilizes TCP port 443. It also uses 465 port for secure SMTP, 993 port for Secure IMAP and 995 port secure POP.
• L2TP utilizes TCP port 1701.
• PPTP utilizes TCP port 1723 and IP port 47 GRE.

Why use VPN

Following are the reasons why use VPN:
• People who are away from office and would like to use office intranet, accounting system or HR system to update leave and daily attendence can use the VPN.
• VPN provides secure internet connection so that one can access sensitive proprietary information using Intranet VPN type.
• To access the content from another country securely using remote access VPN or extranet VPN types.
• To access restricted sites or programs using VPN as it overcomes government restrictions.

Advantages of VPN

Following are the advantages of VPN:
• Companies can extend geographic connectivity. They can boost their employees productivity.
• It provides great amount of scalability.
• It provides secured internet access.
• It is easy to add or remove users.
• It provides mobility to users.
• It reduces long distance telecommunication costs.

Disadvantages of VPN

Following are the disadvantages of VPN:
• Understanding of security concerns for the common man is difficult task.
• Unpredictable internet traffic
• It is difficult to accommodate products from different vendors.
• Lack of standards
• Unknowing use of some free VPN applications may lead to intrusion and breach of security.

Networking related links

Basics of OSI and TCPIP layers
Networking Gateway
What is Router
What is an IP address
network switch
network bridge
Hub and Types of Hub
What is MAC address

What is Difference between

hub Vs switch  circuit switching Vs packet switching  firewall Vs router  HDLC Vs PPP  IGRP Vs EIGRP  router Vs bridge  switch Vs router  WLAN Vs Ethernet LAN  LAN vs WAN vs MAN 

RF and Wireless Terminologies


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