VPN cut off leased lines
A virtual private network is a dedicated communications network over a long physical distance that only certain users can access.
The key feature of a VPN is its ability to use public networks like the Internet rather than private leased lines.
VPN is helpful solutions for remote users and branch offices securely to the networks of small and medium-sized businesses (SMBs). Smaller companies are finding VPNs cheaper to operate than more costly dedicated T1 phone lines.
Head office > ISP > Branch office
There are two types of VPN configurations.
site-to-site:- This is used to connect two networks and involves an exchange of public keys for authentication and encryption.
A site-to-site VPN allows offices in multiple fixed locations to establish secure connections with each other over a public network such as the Internet
remote access:- Client software runs on systems of employees and others authorized to access a company’s VPN. Software creates the VPN tunnel with a key exchange.
Multiple Branchs > Internet > NAS server > Headoffice
A remote-access VPN allows individual users to establish secure connections with a remote computer network. Those users can access the secure resources on that network as if they were directly plugged in to the network’s servers.
Clientsoftware > VPNconnection > NAS server > Server
For Internet-based VPNs, packets in one of several VPN protocols are encapsulated within Internet Protocol (IP) packets. VPN protocols also support authentication and encryption to keep the tunnels secure.
voluntar:-In voluntary tunneling, the VPN client manages connection setup. The client first makes a connection to the carrier network provider (an ISP in the case of Internet VPNs). Then, the VPN client application creates the tunnel to a VPN server over this live connection.
compulsory:-In compulsory tunneling, the carrier network provider manages VPN connection setup. When the client first makes an ordinary connection to the carrier, the carrier in turn immediately brokers a VPN connection between that client and a VPN server. From the client point of view, VPN connections are set up in just one step compared to the two-step procedure required for voluntary tunnels.
VPN Tunneling Protocols
Point-to-Point Tunneling Protocol (PPTP)
The initial releases of PPTP for Windows by Microsoft contained security features that some experts claimed were too weak for serious use.
Several corporations worked together to create the PPTP specification. People generally associate PPTP with Microsoft because nearly all flavors of Windows include built-in client support for this protocol.
Layer Two Tunneling Protocol (L2TP)
L2TP protocol primarily implemented by Cisco.
Internet Protocol Security (IPsec)
IPsec is a collection of multiple related protocols. It can support encryption scheme within L2TP or PPTP. IPsec exists at the network layer (Layer Three) of the OSI model.
Microsoft VPN server 2003
Here i found good article for 2008
VPN Connections in Windows XP
Control Panel > Network connections > create new connections > connect network at my workplace > VPNconnections > Enter name of VPN connections > Choose any option of ‘Automatically dial this initial connection’ or ‘Do not dial the initial connection’ > Enter the name or IP address of the VPN remote access server > In option on the “Connection Availability” ,the default option, ‘My Use Only,’ ensures that Windows will make this new connection available only to the currently logged on user. Otherwise, choose the ‘Anyone’s use’ option > Complete the wizard.
Best Top VPNs
using VPN software on a router, server, firewall, or gateway is usually seen as a relatively low-cost way to deploy a VPN,but limited to the performance.VPN tunneling and encryption tasks will be carried out in software, taking CPU cycles from other processes.
In such cases , many router and firewall vendors offer add-on, hardware-assist products for heavy-load VPNs.
VPN service providers for SMB
There are several VPN services for small businesses, but the most common is broadband VPN,which gives remote users the same speed experience they would have in the office.
Some of the recommended VPN services and products for SMB are SonicWall,Cisco ,3Com.
Steganos offers four different VPN products for SMBs. These are Steganos Secure VPN, Steganos Secure VPN Premium, Steganos Secure Traveler and Steganos Secure Traveler Premium.
Check Point provides SMB users with an appliance-based VPN appliance. Two models are available. The basic model includes a firewall and the VPN appliance. A second model provides for an unlimited number of users.
Untangle offers two products for the SMB user. Open VPN requires less in-house technical knowledge. It uses a configuration wizard. Open VPN is free forever regardless of the number of users. Untangle also offers Remote Access Portal, a product for remote access through a Web page.