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Linux & DSL
Power, Speed and Savings
For those of you who haven't yet heard of DSL, check out
this site for more details. If
you're a business in need of a fast, cheap Internet connection or just
someone who wants to get at the Web at blazingly fast speeds and not pay
through the nose, DSL is for you. SpinnNet offers DSL net access at
speeds that will fit any budget. This page isn't about that though, this
page is for those of us who use Linux and want to know what DSL offers
us. And believe me, it offers a lot.
One of the most important things about Linux is the price. I'm not
just talking about the fact that you can download it for free or order CDs
for $2, I'm talking about how
Linux lets you do important things on a cheap machine that you probably
would have thrown away before Linux came along. One of the most important
things Linux can do for DSL users is to act as a firewall and save you the
cost of an expensive router. Linux can also let you use a single IP
address to let many machines behind the firewall access the net.
Linux as a firewall/router
For an excellent article detailing all the steps and precautions you need to
take care of for your Linux firewall, check out
this article
at SecurityFocus.com.
What you'll need:
- a cheap 486 or old Pentium
- 2 10 baseT Ethernet cards (ISA or PCI, depending on your machine)
- an internet connection (since you're reading this doc, you should be
all set)
- some time
Something that is new to most DSL users is the idea of having a
"persistant connection." What this means is that unlike a modem where you
have to dial SpinnNet and connect, DSL is always connected. That's right,
no more waiting for dialing to check your email or look up
driving directions. Using the Yellow Pages is even easier once you're
always online. There is one issue that needs to be addressed, however, and
that is security. If you're reading this page, you probably use or know
about Linux. That means that you care about your computer. Windows98/95
has no security so if you run those legacy operating systems, you'll need
a Linux box to help protect your data. Even if you use Linux on your home
machine(s), a Linux firewall can help protect those machines even more
than they are already.
If you're a home user, your data is probably pretty safe due to the
fact that really, nobody cares about your stew recipe or your letter to
your grandma. You should still care about security however, because
crackers have been known to use computers they cracked to attack other
systems. If you're a business, security is probably more important to you
so you might want to consider hiring a network security company or buying
one of the commercially available firewall packages. The info is this
document should still be useful to you however.
Getting going
Get that old 486 or Pentium, blow the dust off of it, power it
up and install Linux on that guy. Unlike users of Windows, Linux users do
not have to upgrade our systems every 6 months, Linux makes even old
hardware live again. This new cheap box will be your firewall. Keep those
2 Ethernet cards handy.
The first document you need to read is the Linux Firewall
HOWTO. If I were to write about how to make a firewall, I would just
be plagarizing this HOWTO so here's the original. It'll point you to the
Ethernet
HOWTO, which shows you how to install those 2 Ethernet cards.
Once you've got your firewall machine up and running, you should
plug your DSL modem into the Ethernet card you specified as the "incoming"
card, then plug from the other card into your machine or into a router/hub
so many machines can be connected to the net if they are on your home
network. This way you can all the machines in your house on the net and
not have to fight with your kids/spouse/dog over whose going to get on the
net when. If you want to use many machines behind your firewall, you'll
either need a router with NAT (which are expensive enough that if you can
afford one, you probably wouldn't need this document), or you'll need to
setup IP
Masquerading. IP Masquerading is what lets you use 1 IP address for
multiple machines. With IPMasq, you can have up to 16777216 machines in
your house on the net (if you use 10.X.X.X for your inside addresses) To
me, this alone justifies the use of a Linux machine
as a firewall/router, since DSL routers that have multiple ports are $200
more than DSL modems with only 1 port. Plus, you'll pay more for
more IP addresses since there are only so many to go around and nobody
can just hand them out anymore.
All in all, if you want to take the time to get things going,
setting up a Linux box as a firewall/router to use with your DSL line is a
winning proposition. It helps with security, it allows more flexibility in
setting up your home for net access, and it saves you money. I recommend
taking a Saturday, sitting down with the HOWTOs I've pointed you to and
getting things going. You'll be glad you did.
Remember, if you need help with your SpinnNet DSL line and Linux, feel
free to give us a call at 938-7746 or email
support@spinn.net