 VPN - Virtual private Networking, an
overview A VPN is a secure, private communication
tunnel between `two or more devices across a public network (like
the Internet). These VPN devices can be either a computer running
VPN software or a special device like a VPN enabled router. It
allows your home computer to be connected to your office network or
can allow two home computers in different locations to connect to
each over the Internet.
Even though a VPN’s data travels across a
public network like the Internet, it is secure because of very
strong encryption. If anyone ‘listens’ to the VPN communications,
they will not understand it because all the data is encrypted. In
addition, VPN’s monitor their traffic in very sophisticated ways
that ensure packets never get altered while traveling across the
public network. Encryption and data verification is very CPU
intensive.
Clients and Servers
A VPN server is a piece of hardware or
software that can acts as a gateway into a whole network or a single
computer. It is generally ‘always on’ and listening for VPN clients
to connect to it.
A VPN Client is most often a piece of software
but can be hardware too. A client initiates a ‘call’ to the server
and logs on. Then the client computer can server network can
communicate. They are on the same ‘virtual’ network. Many
broadband routers can 'pass' one or more VPN sessions from your LAN
to the Internet. Each router handles this differently.
VPN Software
VPN ‘server’ software is rather rare. Windows
Server level operating systems like ‘Windows 2000 Server’ have a
‘VPN server’ built in. I know if no software products priced for
home or small business that allows you to set up a VPN server.
VPN ‘client’ software is much more common.
When loaded on your computer, this software allows you create a
secure VPN tunnel across the Internet and into another network
fronted by a VPN server.
VPN Languages
There are two major 'languages' or protocols
that VPN's speak. Microsoft
uses PPTP or Point to Point Tunneling Protocol and most everyone
else uses IPSec - Internet Protocol Security. Most broadband routers
can pass PPTP traffic by forwarding port 1723 but IPSec is more
complex. If your router does not explicitly support IPSEC pass
through, then even placing your computer in the DMZ might not
work. PPTP has 'good' encryption and also features
'authentication' for verifying a user ID and password. IPSec is
pureley an encryption model and is mutch safer but does not include
authentication routines. A third standard, L2TP is IPSec with
authentication built in.
|
VPN Reviews |
2/18/2002: SnapGear Lite+ VPN Router (read) |
2/12/2002: ZyWall 1 - Firewall and Router
with VPN (read) |
1/24/2002: Multitech RouteFinder RF550VPN
(read) |
1/3/2002: Draytek Vigor2200E & USB
VPN Routers (read) |
Broadband Routers with VPN Servers
Until recently, VPN server hardware was VERY
expensive. As home networks become more sophisticated, the demand
for home level VPN’s increase. At the end of 2001, the home
network industry responded by adding VPN servers into some broadband
routers. These products are often priced at under $300 (us) and some
are as inexpensive as $170.
VPN functionality is very processor intensive
and most broadband routers have somewhat slow processors in them.
Broadband router based VPN servers are often limited in throughput
because of their microprocessors. Most have a maximum VPN throughput
of around .6Mbps or 600Kbps.
More info about VPN Routers
soon!
Outside Links for more
info
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VPN Tutorial - Virtual Private Network
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