In This Issue
Smoking Is Dumb: Young Men Who Smoke Have Lower IQs,
Firefox regains some lost browser share ground
Welcome to our Newsletter
What is a Firewall? Do I need one? Am I
really protected? I have been asked these
questions many times. Below is an article
explaining Firewalls and what they are and
how they work. Every situation is different,
let us help you choose the correct Firewall
for your needs.
I'm not sure if everyone knows yet. We
moved our office. We needed more space so we
moved into a larger office suite in the same
building. Our new office address is: 420
North Sacramento Street, Suite #6, Lodi,
California 95240. The phone number remains
the same 209-368-5252.
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phrase "There's no such thing as a Free Lunch." Well, here it is. If you refer a
new customer to us and that customer results in a minimum of one hour of
computer service, YOU will receive a $10 gift card to spend at a local
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Hardly a day goes by without my
inbox stuffed with news of a new
virus or worm and even worse a
vulnerability discovered in some
program I'm using. Of course you
can't ignore issues like these but
there are steps you should be taking
to sleep well at night. Anti-virus
software is a must but that is only
half the battle. You need to be able
to keep unwanted visitors out and
sensitive data in and that's the job
of a firewall.
What is a firewall?
In simple terms a firewall is a
hardware or software device that
acts like a fence around your system
or network. It would be great just
to put up a big fence and never let
anyone in. By doing that, you would
lose all communication with the
So what is needed is a walled garden
with access to and from a limited
amount of applications and data that
you trust. That is exactly the job
of a firewall. Of course they range
from free software only firewalls to
full corporate wide hardware
How does it work?
There are a number of technologies
employed by firewalls to protect
your data and network, the first is
a simple set of rules. This
permission based scheme plugs the
holes that Windows operating systems
are sadly renowned for. Your Windows
operating system has many holes in
it, some must remain for
applications like email and web
browsing to get to the Internet, but
Windows ships with many other holes
or "ports" open.
For example, many home machines will
never network with another machine
in their entire life, but as
standard they ship with the NetBIOS
ports open. There are a number of
viruses and hacking tools that
exploits this simple fact and there
is an equally frightening number of
home PC's right now with this port
A simple rule set starts from the
position of all ports (or doors)
closed and then as you start each
application you have to create a
rule to let it get to the Internet
or network. Most firewalls will come
configured to allow Internet and
pop3 email access from start-up but
you'll find that instant messaging
like MSN messenger and Yahoo IM will
need permission to work.
What types are there?
There are 2 physical types of
firewalls, software and hardware.
Software firewalls are commonly used
in the home environment. Big names
like Norton and MacAfee both make
and sell Internet personal
firewalls, these do a pretty good
job of providing a basic rules based
protection system by running an
application on your PC.
Hardware firewalls are more common
in business environments where
dedicated units have the outside
world plugged in on one side and the
trusted network on the other. These
are often supplied as a pair so that
failure of a unit does not make the
Both hardware and software firewalls
use a number of different techniques
to keep your PC and network safe.
All data incoming and outgoing is
inspected to see that it is coming
from and going to trusted ports on
the system and possibly even trusted
The next level up is a proxy server,
this stands between the outside
Internet and the trusted network. It
intercepts all packets of data and
checks if they meet the packet
filter rules before forwarding data
to the machine inside the trusted
network. This adds a level of
security by never letting the
Internet machine talk directly with
the trusted machine. A system of
Network Address Translation (NAT)
hides your internal IP address from
the Internet meaning all data has to
go through the firewall for
inspection. A proxy server is very
good against brute force attacks,
the equivalent of someone trying to
shoulder charge your door down, its
like putting an extra set of doors
between your machine and the attack.
The best level of firewall
technology is normally found only in
high end firewalls but is slowly
creeping into the top end home
devices. This not only applies rules
to incoming data it checks various
security protocols and can determine
if data is really from whom it
claims to be. This is in effect a
smart firewall which is looking for
known characteristics of certain
attacks and spoofing attempts.
Most firewalls use at least 2 of
these techniques and the best
firewalls are a combination of all
three. Plus most corporate firewalls
use a combination of hardware and
software to protect their networks.
Do I really need a Firewall?
Well it depends, most dial up users
would not benefit from the extra
security and would be hindered by
the downsides covered in the next
section, as dial up users get
assigned a new IP address every time
they connect it would be very
difficult for hackers to find the
machine before you end your surfing
With broadband you should get some
kind of firewall protection, For
example, a computer connected to a
broadband connection will keep the
same IP address until rebooted.
That's the only time your ISP gives
a new IP address.
So a broadband user connected for
enough time would make it worth
while searching for open ports and
trying to get in, or for a Trojan
program on a machine inside a
network to get out and do some
There must be a downside to
Of course there is some downside,
almost all firewalls have some
performance issues. Anything above
the simplest packet inspection
system will slow down traffic in and
out of your network. Not by much but
it will have an effect. On a
broadband connection this is hardly
noticeable but on dial up its just
another drain on a small 56k
connection. Also some of the
software based firewalls eat system
resources on the host PC.
What should I get and where
do I get it?
If you decide that you should look
at protecting your single PC and do
not plan to build a network, then a
software system would be sufficient.
If you have a network then the best
bet for the home user is a router
with a firewall, be it wireless or
cabled manufacturers offer
competitively priced devices with a
good solid firewall.
We would be glad to discuss your
needs and suggest appropriate
solutions. Call Today.
If you have a particular question or subject in mind,
note and we will share some information on the subject. Reader input is the key to
a useful newsletter.
For more information, tips and resources
I hope you find this information
interesting and useful. If you have any
questions or need further information.