User`s guide

interface directly with the hardware installed in the computer. By allowing this, software writers

do not have to work with poorly written or tightly managed library components, as they do in

Windows. However, this increased functionality does come with its share of problems.

Because of the nature of open source software, you can never be sure what is included in a

package, or how it will work with a certain piece of software. Whereas one program might work

flawlessly right out of the box, another program might require several additional operating

system components or tweaks to existing files before it will run. However, Ethereal is fairly

stable across the various Linux platforms, as long as you ensure that the configuration file is set

up correctly.

3.2.3.1 Requirements

Ethereal for Linux has several prerequisites. By meeting these requirements before you

attempt to install the software, you will have a relatively easy installation process. Some of these

prerequisites are not necessary for the core functionality of Ethereal; however, they will add

extra features to make it more productive.

NOTE

Although each of these prerequisites does have its own home page, you can get them all

from the local archive at http://www.ethereal.com

• GTK+ and Glib (http://www.gtk.org)—This program is the de facto standard

toolkit used to create GUIs in the Linux environment. Ethereal requires this

program for installation.

• Libpcap (http://www.tcpdump.org)—Libpcap for Linux is required by Ethereal to

facilitate the capture and formatting of the data from the NIC. Ethereal

requires this program for installation.

• Perl (http://www.perl.com)—Perl is the programming language of choice for

small projects in the Linux environment. Ethereal uses it to build the documentation.

• Zlib (http://www.info-zip.org/pub/infozip/zlib)—Zlib is a compression software

library that can be installed with Ethereal to facilitate the reading of

compressed gzip files on the fly. This program is optional for Ethereal.

• NET-SNMP (http://net-snmp.sourceforge.net)—NET-SNMP is a software library

used to read and write SNMP data. Ethereal uses this optional component to

decode captured SNMP data.

3.2.3.2 Installation Options

Installing Ethereal requires several steps. You should be somewhat familiar with the general

installation process before attempting to perform this process. Install scripts typically request

various configuration settings, such as your source directory, module directory, and more.

However, for those who do not want to run through the manual building of source code, RPM

files are available for download. The following briefly describes the general steps involved in

installing from source code and in installing from RPM. As you can see, using the RPM is much

simpler. Installing RPMs Use the following format to install RPMs. This should result in a

complete install, without the need to configure or install source code.