Bridge the gap with a VPN – Part 1

It is common these days for every site in the enterprise to be connected to the Internet in some manner. Whether it's DSL (digital subscriber line), cable, or T1 line, businesses can always justify the use of a solid Internet connection for business productivity.

But how can you leverage all of the resources on these separate, private, networks without getting dedicated data lines to link them all together?

The answer this week is VPN.

VPN, or virtual private network, is a network used for internal communications across the corporate computer systems. The keyword in VPN is “virtual”.

To get a better understanding of the VPN structure think of the wired network in your office. You have a couple of computers and servers plugged in to a network switch. These computers are all on a LAN (local area network). Their communications are confined within that LAN and mostly likely are securely tucked away from the Internet.

A VPN takes the same concept and extends the communications across virtually unlimited distances. Essentially, a computer in California can communicate with a server in Florida as if it were plugged in to the same switch, all across the Internet.

This gives new meaning to the extended network and allows you to spread resources across multiple locations by linking private networks securely over normally unsecured channels.

The big buzzwords in VPN is security and encryption. It is easy to see why this is a hot button. If we allow users to access critical file shares across the Internet we have to do it in a secure manner.

Now, knowing that the Internet is a big jungle and a “not-so-secure space”, how do we transmit data between offices without other people hijacking our information?

This is accomplished in a couple of different ways. First, many devices that communicate on the WAN will provide encrypted tunnels between the sites while establishing the VPN. Users may have a VPN connection setup within Windows that authenticates them against a VPN server within your internal network.

Once authenticated, the user is on the VPN and able to access resources as if they were in the office. Also, data that is passed from one site to the other is sent across an encrypted pipeline (or tunnel) that cannot be read. This is a must when using any Internet connection as the link to your VPN.

For some businesses, there are other solutions such as hosted-VPN or MPLS (multi-protocol label switching). I will touch on these solutions and dive into a bit more technical information on VPN's in next weeks' column.