Re: A good firewall working fine in default?

Duane Arnold wrote:

> A NAT router works fine in its default state out of the box. It takes
> little or no configuration on your part and is easy to learn.
>
> http://www.homenethelp.com/web/explain/about-NAT.asp
>
> Duane :)

I've tried testing what you have said here and in previous threads. I
have turned off Zone Alarm
and the only defense (excluding AV program) that is between me and the
internet is my Linksys router - BEFSR41 - 4 port, stating on the box
that it has NAT technology.

I went to grc.com and their tests say all ports are secure.

Next I went to testmyfirewall.com and to my surprise I get this message:

                     INTERNAL IP EXPOSED
                     xxx.xxx.x.xxx
(I put x's for the numbers so as not to give out my settings)

The message below came from the spyware testpage. I couldn't get it a
second time so I'm wondering what's going on. I set my browser (IE) to
default setting again so maybe that was why I got it only once.

Internal IP address

NATTED IP
Your external IP address (xx.xx.xx.xxx) is always exposed to the
internet, if it wasn't, you wouldn't be able to visit sites. On the
other hand, your internal IP address (xxx.xxx.x.xxx) should be protected
and not be obtainable by websites.

Internal IP
This does not necessarily mean your firewall is malfunctioning or
improperly configured. The method we used will sneak past most
firewalls. Why? Because we use Java to grab the information and then
pass it on to the server (Notice how everything ran without prompting you?)

Private IP - Why you're Vulnerable

We used your internal IP for this demonstration because it's harmless
(for the most part). Java passes this information to the server were it
can be collected. Many claim this is not possible and that only you can
see this information, so to prove the point, we included the last 20
internal IP addresses that this server has seen. To verify this
information, simply tell a friend your Private IP and have them visit
this page shortly after you do - they'll see your IP included in the list.

Private IP - What is it?
Private IP addresses range from:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255

IP Privacy
A hypothetical example of using your internal IP address to track your
activities is an internet service provider. Some cable companies charge
you for each computer connected to your cable modem. By tracking your
internal IP address, the cable company could see that you're running
multiple computers on one router and bill you accordingly.

More to Security than a Firewall!
The whole point of this demonstration is to make you aware that there is
more to security than just a firewall. A malicious website owner could
use a similar method to grab a lot more than your internal IP address,
and you wouldn't even know it!

Duane, check it out and see what you get.
Received on Mon May 1 00:50:33 2006