Under Construction

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.

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

[BACK]