Bullet-proof your email

So you're back online after another vicious attack on your computer. 
You're sick of all the troubles you've been having.  How are you going to
prevent this kind of this from happening again?  Consider using an email
program that is nearly virus proof, like Pine, a text-based program that
composes and displays text email, which is, after all, what email was intended
to be.

Microsoft Outlook and Outlook Express are huge targets for attackers because
they're hugely popular (Outlook express comes with every new Windows computer)
and because there are so many features to exploit.  Don't get me
wrong.  The features Microsoft build into their software help make using it
easy and pleasant -- for the most part.  But remember that the more bells
and whistles you build into a program, there more places there are for breakage
(and expoits) to occur.

Old-school computer users sit back and chuckle at all the troubles people
have with their fancy-schmancy, graphics laden, gadget-heavy computers. 
The old-schoolers not only remember the good old days of text-only email, but
many still use it exclusively.  Let's look at an email program called Pine. 
It was designed for use on Unix computers and is ported to many other operating
systems, like Linux and even Windows.  Later versions of Pine strip HTML
coding from messages and display them as plain text.  Attachments can be
easily detached and stored without executing them.

How can I do text-only email?  There are several possibilities. 
You might, for instance, have shell access to your email account.  If this
is the case, perhaps you can use pine in a telnet window on your computer. 
If you don't have shell access available to you from your ISP, then build your
own server machine out of an old computer you have laying around the house.

If you have or can come up with an old 486 or early Pentium-class machine
that has 32 or more megs of RAM, you can install a network card and a free
distribution of Linux; set it up to fetch mail from all your outside POP3 and
IMAP accounts (it won't work with free web-based mail like Hotmail and Yahoo!
without some external programming); then logon and type 'pine' at the command
prompt and start corresponding.  Chances are, you'll never have a virus
problem again.  You'll not only have a full-fledged email server, but the
added features of a file and print server too, and at no more cost than the old
computer you already own!

Gateways vs. Access Points

Some time ago, I had an occasion to set up a wireless network for some
friends.  They had a broadband connection to the Internet through a cable
modem provided by Mediacom and two desktop computers.  I suggested they buy
an 802.11b gateway and 802.11b cards for each computer they wanted connected.

After installing and connecting all the hardware they bought, each computer
seemed to be able to connect to the Internet fine, and we were able to do some
file and print sharing between them.  But it all wasn't fine.  I
quickly discovered that the computers could surf the net, but not at the same
time.  It is then that I discovered that they'd purchased an access point
and not a gateway.

A wireless access point does one thing.  It broadcasts a single RJ-45
jack to multiple wireless network cards.  It merely provides direct
connectivity to the public.  In this case, the public network sees all the
computers connected.  This is a problem because Mediacom (and many other
cable companies) will only assign you one IP address.  Not one for each
computer you have plugged into their network, just one period.  So when we
connected the AP and fired up the first computer, we were fine.  Mediacom
asked us to verify our new mac address, as expected.  Then we fired up the
second computer.  And again, we were asked to verify the mac address. 
Doing this, we got on the net with that machine too.  So all's well, right?

Wrong!  Being asked to verify a new mac address the second time was a
bad sign.  It meant Mediacom could see the mac addresses on each machine,
which told us that the wireless base was not fronting for us, but was exposing
each machine attached to it to the network, requiring each machine to obtain its
own IP address, which Mediacom will not do for more than one machine
simultaneously.

Ah hah!  It's an access point, not a router.

If my friends had purchased a wireless gateway instead of the simple wireless
access point, the gateway would have appeared to Mediacom as a single computer,
and only asking to update the mac address once, and that mac address would have
been for the gateway and not one for each of the computers.  With a
gateway, we not only insulate each of the internal computers from the Internet,
but we sort of fool Mediacom into thinking we only have one machine connected to
their network.  A gateway acts as the go-between for all Internet requests
coming from inside the network -- so instead of each computer requesting its own
IP address from Mediacom directly, each computer would ask the gateway (and not
Mediacom) for their IP address, which would in turn assign each machine a local
IP address from a bank of local subnet addresses.

Lesson learned.  Access points are fine if you're already behind a
firewall and are not limited to the number of IP addresses you can
request.  But if you're using a cable or DSL modem, make sure you use a
gateway to connect several computers to the network or you may have the same
problem we had.

Wireless home networking update:

Lots of people assume that you need
broadband (cable or DSL modem) to have wireless networking.  Not
so.  You can still use your single dialup connection and share it
with all users on your home or office network.  But there are a few
complications, including slower surfing and downloading.

In order to share dial up internet, you
need to have a modem doing the dialing.  There are a number of ways
to get dialup internet into your network, but none are all that common,
or even very easy:

• A dedicated server, such a
  Linux computer with a modem and a
  network card.  This machine will act as a gateway between the
  Internet and your local network.  Whenever someone tries to get
  on the net, the server will make a dialup connection.  You can
  also use it as a file and print server.  The advantages here
  are that can be very cheap to set up and use and it is extremely
  feature-packed -- but the downside is that it's very complicated to
  setup and maintain.


• A Windows computer that is
  turned on and available to dial up the ISP whenever someone on the
  network wants to get on the Internet.  More expensive, but
  easier to set up.


• A gateway device that has a
  built-in modem, designed specifically to provide dialup access to
  the Internet in this way, such as the base station one below.

Here's what I suggest for most home/small
office users on a shoestring budget:

The base station is a href="http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=ZoomAir+Wireless+IG-4150+Wireless+Gateway"
target="_blank">ZoomAir Wireless IG-4150 Wireless Gateway for under
$70, connected to either your phone line (56K dialup) or your Cable/DSL
modem (usually 256Kbps to 1,500 Kbps).  What makes this unit unique
is that it has a built-in 56K modem where most all Gateways/Routers do
not.  Those gateways and routers that do facilitate 56K dialup
connections to the Internet only do so through a serial port which you
must connect an additional external modem.  The ZoomAir Gateway is
configured to dial and logon to your ISP using a web browser.  I
assume this is a dial on demand situation, so that whenever a computer
needs an Internet connection, the modem will make that connection, and
hang up after a period of in-activity.

The downside of using this
particular gateway is that computers and the software running think
they're always connected to the net, so may make frequent connections
to update software such as weather bugs, chat clients, anti-virus
software definition updates and automatic Windows updates, and
therefore may never be inactive.  This can increase your ISP
service charges if you are billed on an hourly basis.  It would
be beneficial if you could configure the modem to ONLY dial up during
specific hours of the day, so that you could 'throttle' usage to stay
below a certain number of hours a month.  I have no idea if this
feature is built into this gateway.

802.11b Wireless network adaptors
for all computers on your network.

• A laptop should use a href="http://www.compusa.com/products/product_info.asp?product_code=279434&pfp=BROWSE"
  target="_blank">wireless PC Card, ( href="http://www.zoom.com/graphics/prod_shots/4150photo.JPG"
  target="_blank">Photo.) which is a PCMCIA card that slides into
  a PC Card (PCMCIA) slot on almost all laptop/notebook
  computers.  Any brand will do, but it must be 802.11b
  compliant.


• Desktops use an internal href="http://www.compusa.com/products/product_info.asp?product_code=292350&pfp=BROWSE"
  target="_blank">wireless PCI card.  Again, any brand will
  do the job, but make sure it's 802.11b compliant.

How it works:

The base station connects to the internet
through either the phone line or your cable or DSL modem.  It then
sets up a private local area network, isolated from the outside. 
It assigns local IP addresses to each computer that connects to it in
ranges that are not accessible from outside your LAN and Internet
connection.