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Disadvantages of VPNs
With
the hype that has surrounded VPNs historically, the
potential pitfalls or "weak spots" in the VPN model can be
easy to forget. These four concerns with VPN solutions are
often raised.
1.
VPNs require an in-depth understanding of public network
security issues and taking proper precautions in VPN
deployment.
2.
The availability and performance of an organization's
wide-area VPN (over the Internet in particular) depends on
factors largely outside of their control.
3.
VPN technologies from different vendors may not work well
together due to immature standards.
4.
VPNs need to accomodate protocols other than IP and existing
("legacy") internal network technology.
Generally speaking, these four factors comprise the hidden
costs of a VPN solution. Whereas VPN advocates tout cost
savings as the primary advantage of this technology,
detractors cite hidden costs as the primary disadvantage of
VPNs
What
Exactly Is A VPN?
A
VPN supplies network connectivity over a possibly long
physical distance. In this respect, a VPN is a form of WAN.
The
key feature of a VPN, however, is its ability to use public
networks like the Internet rather than rely on private
leased lines. VPN technologies implement restricted-access
networks that utilize the same cabling and Routers as a
public network, and they do so without sacrificing features
or basic security.
A
VPN supports at least three different modes of use:
Remote access client connections
LAN-to-LAN internetworking
Controlled access within an intranet
VPN
Pros and Cons
Like
many commercialized network technologies, a significant
amount of sales and marketing "hype" surrounds VPN. In
reality, VPNs provide just a simple few clear potential
advantages over more traditional forms of wide-area
networking. These advantages can be quite significant, but
they do not come for free.
The
potential problems with the VPN outnumber the advantages and
are generally more difficult to understand. The
disadvantages do not necessarily outweigh the advantages,
however. From security and performance concerns, to coping
with a wide range of sometimes incompatible vendor products,
the decision of whether or not to use a VPN cannot be made
without significant planning and preparation.
Technology Behind VPNs
Several network protocols have become popular as a result of
VPN developments:
PPTP
L2TP
IPsec
SOCKS
These
protocols emphasize authentication and encryption in VPNs.
Authentication allows VPN clients and servers to correctly
establish the identity of people on the network. Encryption
allows potentially sensitive data to be hidden from the
general public.
Many
vendors have developed VPN hardware and/or software
products. Unfortunately, immature VPN standards mean that
some of these products remain incompatible with each other.
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