Network Uptime

Linux/Unix LiveCD Distributions

If you’ve not used a Linux- or Unix-based bootable CD before, you’re missing enormous functionality that requires almost zero setup and configuration time! These LiveCD distributions are perfect tools for system recovery, network security, network analysis, or everyday Internet browsing. There are many specialized builds of bootable CDs that include home entertainment, firewalls, system recovery, gaming, medical applications, and even geographic information systems (GIS). One of the most comprehensive distribution lists is found on The LiveCD List, and there’s probably an available distribution that will fit your requirements!

Choosing a LiveCD Distribution

There are hundreds of LiveCD distributions, so finding the perfect distribution could take a lot of trial and error! Fortunately, The LiveCD List has categorized the distributions by their primary functions to help focus the decision making process.

One of the most popular and best supported distributions is called Knoppix. Knoppix is a Linux-based LiveCD that includes OpenOffice, Konquerer, Apache, MySQL, and other general-purpose applications and utilities. Many Live CD distributions maximize their impact by using Knoppix as a starting point for their application collections. If you’re new to LiveCDs or Linux, the Knoppix distribution makes a great starting point.

The Knoppix boot screen (click for large version)

One of my favorite LiveCD distributions is a Knoppix derivation called Knoppix Security Tools Distribution, or STD. The STD contains fourteen different categories, including forensics, firewall, ids, network utilities, servers, packet sniffers, and TCP tools. A copy of Knoppix-STD is always in my traveling CD case!

Obtaining a LiveCD Distribution

Most distributions can be downloaded directly from their home page, which usually lists many other mirrors as alternatives. Download bandwidth is always at a premium with these 700 megabytes ISO images, so a good alternative is to use a BitTorrent link when it’s available.

Once the distribution ISO is downloaded, it needs to be written to a CD. However, simply placing the ISO file on a CD-ROM will not make the CD bootable! Extracting an ISO image requires specialized software that will burn the ISO image onto a CD. Many of the utilities shipped with CD-ROM recorders include the capability to burn an ISO formatted file. This web page or this page has more information on burning ISO files using different operating systems.

Once the ISO file has been recorded to a CD-ROM, it’s ready to use! As long as a computer’s BIOS allows it to boot from a CD, the LiveCD can be started by simply rebooting the system. If your computer won’t boot from a CD, check the BIOS settings or your computer manufacturer’s documentation for additional information.

Using Knoppix Security Tools Distribution

Once a LiveCD distribution is burned, hundreds of applications and utilities are available simply by rebooting the computer! On my computer, I was able to reboot, launch a web browser, start a packet capture utility, and launch graphical network monitoring tool. This screen shot shows the results of just a few minutes of work!

Each STD category is grouped in the main menu, and every category includes its own application shell and RTFM (read the freakin’ manual) shell selections. To look through the documentation in each category, select the RTFM shell and ls (list) the directory of files and directories. To view the documentation, use the Linux ‘more’ utility to page through the included text files. To exit from the ‘more’ utility, press ‘Q’ or ‘Ctrl-C.’

Many of the utilities have graphical clients that can be launched directly from the menus. For example, I ran a Nessus scan from its graphical front-end and obtained a vulnerability assessment for my Internet router in just a few minutes. I didn’t install any software or load any additional software, but I was able to assess the security of my network almost immediately!

Now what?

The Knoppix-STD LiveCD distribution contains hundreds of network security utilities, and a network or security professional could spend days learning the capabilities available in just the STD Linux distribution! I’ll usually carry two or three different distributions in my CD case for network security, general use, or system recovery. Bet you can’t try just one!

Posted by james_messer at April 4, 2005 05:03 PM