Mac Forum / General / Networking / August 2004

sort-of.  Because the internet only sees one IP address for your home
(the one your ISP gives to your router), and your router gives each
system on your home network a non-routing IP address (something like
192.168.*.*, or 10.*.*.*), the outside world has not way of directly
contacting you, so they can not probe for open ports on your various
home systems, they can not use your systems as mail relays, etc...

If you want the outside world to be able to initiate a conversation with
one of your home systems, you have to explicitly tell the router to
forward port nnn to home system nnn.nnn.nnn.nnn.  Otherwise the router
will just drop all such connection requests on the floor.

But stuff you ask for, like web pages, download files, email, iChat/AOL
instant messenger service, etc... will allow you to interact with the
internet, and if any nasties come along that can exploit those channels
on a Mac, then the router will not help there, because you were actually
reaching out to the internet.

Now because you have not listed any PCs on your home network, it is also
unlikely you will receive a virus via an email attachment, or via an
Internet Explorer ActiveX control, etc....  And as long as you keep up
on your Mac OS X security updates, you should be fine.

One side item.  If you are running a wireless network, then depending on
the way you protect your WiFi network, it may be possible for someone to
sit in your driveway (next door, next appartment, etc...) and crack your
WiFi network.  They since that would be local home traffic not traveling
through your router, then if you were concerned, a firewall on your Macs
might be useful.  HOWEVER, how worried are you that someone is going to
try to break into your WiFi setup?  Are they more likely to just want to
use your high speed internet connection for free vs get into your Macs?  
And do not even worry about the government in this, as they can just get
a search warrant and take your computers when them, so we are only
talking about someone local that would want to get at your systems.  If
you are a typical home Mac users there is not much worth going after on
your Macs, and the most valuable thing to them is using your high speed
internet connection for free.  Much too risky breaking in if they live
near by as it makes it much easier to find them if you have less people
to investigate :-)

Anyway, that is my 2 cents.

                                       Bob Harris