I am a TOTAL noob with linux and the "version" of linux i am using is knoppix off of the CD, Anyway, I have been told that network flaws can be checked with Nmap from insecure.org o i was wondering if someone could help me understand what i need to type to install software in linux to keep my network safe

Nmap is a tool that scans for open ports on a machine. It will scan the localhost address by default that will more likely show many open ports from a default linux install. The best way to see what is actually open to the public is use a portscanning tool on a second computer to scan the first one.

or

If this machine is connected to the internet directly. computer to modem wheteher dail-up or broadband then goto sites that will scan your computer like http://www.hackerwatch.org/probe . If you have broadband and a router between your computer and the modem then this scan will only scan the router which is also the only thing anyone can see from the outside. Default store bought routers have no port forwarding enabled as far as I know. Manual should talk about open ports and stuff.

If there is no router the best thing to do is install a firewall tool of somekind like shorewall. There are serveral to choose from. The install you have may already have a firewall installed, configured and runiing at this time. Do not know if Knoppix Live CD do. Probalby find that out on there site faq or search around here or the internet.

Brian1

Once you boot the knoppix cd open a terminal and type nmap

You'll get a lot scroll across the screen. The last line on the help will be

nmap -v -sS -O www.my.com 192.168.0.0/16

copy, paste and edit as desired, for example my target is 192.168.99.1

nmap -v -sS -O -P0 192.168.99.1

You can also run nmapFE from a terminal to get a GUI for nmap. Might not be included in knoppix live.

This should get you started with nmap.

I would follow Brian1's advice and pickup a router if you are on broadband.