Learning how to read the internal workings of
captured packets gives an attacker (or security professional) a keen advantage
instead of just depending on logs for review. If an attacker can alter the data
stream, the logs will represent the altered data.
Procedure:
Install the Ethereal application from either the accompanying
CD or after downloading it from
http://www.ethereal.com
. If you
are installing Ethereal on a Windows computer, you will also need to
install the
WinPcap
packet capture library (also available on the CD
or the Ethereal Web site).
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Practical Hacking Techniques and Countermeasures
To Install Ethereal on a Red Hat Linux Computer:
From the Linux directory containing the compressed Ethereal file, type
tar ??“zxvf ethereal-0.10.13.tar.gz
.
The contents of the compressed file will be installed to a new directory
named
ethereal-0.10-13
.
Change to that directory by typing
cd ethereal-0.10.13
and press
Enter
.
The contents must now be compiled to the specific machine it is on
by typing
./configure
.
Sniffing Traffic
197
The Ethereal code will now compile.
*Note:
Be patient with this step. Depending on your computer this process can take
10 to 20 minutes.
The next step is to type the
make
command, which will create the Ethereal
executable file.
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Practical Hacking Techniques and Countermeasures
The executable is now created.
Now that the Ethereal executable has been created, start the application
by typing:
.
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