TRAINING REPORT ON
SYS - FIREWALL
Secure Your System
A handy tool for System-Administrators
Chandra Prakash Pathak
Maharishi Arvind Institute of Engineering and Technology, Jaipur
Company Profile- Linux World
• The best awarded Red Hat partner in India.
• The company has been contributing a great
deal to Linux Server & Networking industry by
fulfilling its need for trained manpower in the
field of Linux support, Networking, System
Integration & Programming.
What is a Firewall?
A firewall is hardware, software, or a combination of both that is used to
prevent unauthorized programs or Internet users from accessing a private
network and/or a single computer.
How does a software firewall work?
• Inspects each individual “packet” of data as it
arrives at either side of the firewall
• Inbound to or outbound from your computer
• Determines whether it should be allowed to
pass through or if it should be blocked
• Allow – traffic that flows automatically
because it has been deemed as “safe” (Ex.
Meeting Maker, Eudora, etc.)
• Block – traffic that is blocked because it has
been deemed dangerous to your computer
• Ask – asks the user whether or not the traffic
is allowed to pass through
What a personal firewall can do
• Stop hackers from accessing your computer
• Protects your personal information
• Blocks “pop up” ads and certain cookies
• Determines which programs can access the
What a SYS firewall can do
• Authorizing users
• Limiting access for the services
• Filtering the packets
• Linux Kernel 2.4.x or higher
• Perl 5.6 or higher
User interface with “dialog”
dialog --title “Linux dialog utility infobox”
--backtitle “Linux shell script tutorial”
--infobox “This is a dialog box called infobox,
which is used to show information on the
screen, Thanks to Savio Lam and Stuart
Herbert to give us this utility. Press any key…”
• Using Perl and dialog I build a GUI version of
Perl – For coding purpose
dialog – For Graphical User Interface
How does it work?
• Step 1 – Run the application (perl sys.xls)
• Step 2 – Check required packages