[Dshield] Firewall Analogy

Andy Streule andy.streule at lythamhigh.lancs.sch.uk
Mon Feb 9 10:42:33 GMT 2004

I wrote this at work for our users, it sort of grew by itself.
it needs a bit of work at the end to tidy it up. instructions on how to use
zone alarm etc. and it doesnt address if people got a firewall they'd
probably let everything in and out defeating the purpose.

Anyway if anyone wants to use it or rewrite it. or whatever feel free. Just
leave our footer on the bottom.


ICT Technician


Anyone who uses the internet regularly at home should have a firewall. what
follows is an analogous explanation of what firewalls are and how viruses
work. It should make sense to anyone.

It's unfortunate but true, that most viral infections are perpetuated by
home users. so the more people that understand what's going on, in easy to
understand terms, the better. Feel free to forward this explanation to
people you know outside school.

A firewall is a piece of software that protects parts of your computer from
the internet. 
There are a number of viruses that infiltrate computers through their
internet connections. 

	Analogy: Firewall 

	Buying a computer is like a buying a house where the windows dont
close properly. Most houses are like this.Every time you go to work you're
leaving your house wide open to burglarly. To solve the problem you build a
12ft wall all the way around the house and put a guard on the gate.  The
firewall is like the wall. You tell the guard who to let in (and out).

Every so often microsoft releases patches to fix discovered vunerable bits
of your computer. You should have autoupdate enabled to automatically
download patches. Here is a help document for windows 2000 & windows XP:
http://helpdesk.fsu.edu/news/2003-08-21.cfm to enable it.
	Analogy: Patch 

	Every now and again the manufacturer of you windows comes round and
makes some adjustments
or replaces some parts. In some cases these replacements enable your windows
to shut properly in others the windows shut enough to prevent some burglars
from entering e.g. fat ones. You have a lot of windows though so they never
all close. The burglars are an enterprising lot as well, always coming up
with new ways to open windows or get though partially shut windows

Since we've mentioned viruses we might as well make an analogy for viruses
via email. 

	Analogy: Email viruses

	The guard on your 12ft wall of course lets through the postman, but
he doesnt have the ability to check the post or parcels for dubious
contents. Some very clever burglars send
gifts with hidden cameras and microphones attached. Unsuspecting recipients
place these very nice looking gifts in their house unaware that anyone is
watching and listening to their every move. These cunning burglars soon
learn their victims window security codes and where the hidden pot of money
is kept. You can imagine what happens next.

	It therefore seems prudent to employ a postage checker to vet all
mail and remove suspicious gifts.

The postage checker is like your virus checker.

	Since burglars are always coming up with more inventive gifts and
more cunningly hidden cameras the postage checker often has to go back to
base to learn about these new methods.

It's a good idea to set your virus checker to automatically look for and
download updates.

	Ocasionally a dodgy package gets past the postage checker. It's wise
to verify who it's from before opening it.

the easiest to use firewall is called "Zone Alarm". there's a free version

click the the submit button on that page and then look for the "download
here" button on the next one. All staff are legally allowed to install the
school's cd of Sophos antivirus, although many new pcs come with a 1 yr
version of Norton Antivirus. If you use your laptop on the internet at home
you should come and see us about getting a firewall installed. 

For further information see an ICT Technician

Created by 
Lytham St Annes High Technology College [January 2004]


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