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Chapter 2: Networking Basics
What is a VPN?
10/100 8-Port VPN Router
A hacker can use this information to spoof (or fake) a MAC address allowed on the network. With this spoofed
MAC address, the hacker can also intercept information meant for another user.
2) Data Sniffing
Data “sniffing” is a method used by hackers to obtain network data as it travels through unsecured networks,
such as the Internet. Tools for just this kind of activity, such as protocol analyzers and network diagnostic tools,
are often built into operating systems and allow the data to be viewed in clear text.
3) Man in the middle attacks
Once the hacker has either sniffed or spoofed enough information, he can now perform a “man in the middle”
attack. This attack is performed, when data is being transmitted from one network to another, by rerouting the
data to a new destination. Even though the data is not received by its intended recipient, it appears that way to
the person sending the data.
These are only a few of the methods hackers use and they are always developing more. Without the security of
your VPN, your data is constantly open to such attacks as it travels over the Internet. Data travelling over the
Internet will often pass through many different servers around the world before reaching its final destination.
That's a long way to go for unsecured data and this is when a VPN serves its purpose.
What is a VPN?
A VPN, or Virtual Private Network, is a connection between two endpoints - a VPN Router, for instance - in
different networks that allows private data to be sent securely over a shared or public network, such as the
Internet. This establishes a private network that can send data securely between these two locations or
networks.
This is done by creating a “tunnel”. A VPN tunnel connects the two PCs or networks and allows data to be
transmitted over the Internet as if it were still within those networks. Not a literal tunnel, it is a connection
secured by encrypting the data sent between the two networks.
VPN was created as a cost-effective alternative to using a private, dedicated, leased line for a private network.
Using industry standard encryption and authentication techniques - IPSec, short for IP Security - the VPN creates
a secure connection that, in effect, operates as if you were directly connected to your local network. Virtual
Private Networking can be used to create secure networks linking a central office with branch offices,
telecommuters, and/or professionals on the road (travelers can connect to a VPN Router using any computer with
VPN client software that supports IPSec, such as SSH Sentinel.)
There are two basic ways to create a VPN connection:
encryption
: encoding data to prevent it from being
read by unauthorized people
IPSec
: a VPN protocol used to implement
secure exchange of packets at the IP layer
