Make your next computer part of a home network
by Matt Giwer, © 2002 [December]

Reasons

  • Old computers remain useful.
  • It allows you cheap and fast backup of files.
  • It can save money.

The usually recommended procedure is at Private Networks and Roadrunner using IP Masquerading Linux Gazette #51. And it works quite well. But if you are not comfortable with the hardware or setting up the firewall this approach may put you off.

And that is where I was a year ago when a second computer became available to me. I had cable internet access but to connect it required a second IP at $10 per month. I think the setiathome project setiathome project is worthwhile but I was looking to acquire a muscle machine for my animation hobby which would require another IP and another $10 per month.

Originally my thought was only to save the extra charges. To do that I found a 4-port Linksys router for $80. It would quickly pay for itself and as I was single a user it would not upset my ISP should they find out. I run setiathome at nice 19 on all three machines.

Set up could not have been simpler. First I connected the router into the cable modem and turned it on. Then I plugged the computers into the router and turned them on. Installation complete. Right out of the box the computers have local addresses 192.168.1.100, .101 and .102.

To make communication possible I set them so they would run sshd on boot up. For Redhat that meant added the line /usr/local/bin/sshd to the file /etc/rc.d/rc.local as Redhat recommends for user added boot programs. With that I use ssh to operate the other machines and sftp to transfer files between them.

My primary motivation for switching to linux from Windows was in addition to the regular crashes every couple months there would be a crash where I would lose data on my hard drive. For backup I started with a 100Meg Zip drive and ten disks. That was cumbersome, annoying and I never had the right things backed up when a crash occured. It was worse than nothing at all. The next approach was a second hard drive which was somewhat better but it started filling up with data. Quickly there was not enough space for backup.

The new machines were the answer. I use their drives.


This is like a sale to a woman. You have to spend money to save money. If you count all the savings this can be worth hundreds.

Now that you have gone beyond dial up to the internet from you home your computers have ethernet cards. If your old computer does not they are cheap and operating systems will recognize them as new after you install them. Connect a router to the cable or ADSL modem and the computers to the router. You now have a computer network in your home. (Think of the bragging possibilities.)

I have set up a little three computer network, a PII/333, Celeron/400 and an AMD/XP1800 all running Redhat linux 7.3 or 8.0.

$BRAG=`2.5 GHz worth of processing power`
$BRAG2=`I don't have that problem on my network at home`

I run setiathome on them at nice 19 to keep them busy. For Windows users, that is the lowest priority something you can control with a .pif file for a program. Instead of retiring out of date computers a 4-port Linksys router keeps them all productive. Any router should work as well but I can only speak to the one I have.

The router is an instant firewall. You don't have to go through pages of arcane instructions on how to make one machine a firewall for the rest. You do not have servers for the outside world on your side of it so a password is the only configuration needed. Even a password isn't needed if you do not enable remote management but it feels safer.

Using Redhat linux all I do is add /usr/sbin/sshd asa line in rc.local so it starts when the computer boots. I use ssh and sftp to get into the other computers. When my "master" computer is in graphics mode as with KDE or Gnome, I can run graphics programs on the other machines with ssh without the other computers being in a graphics mode. I run mozilla on a different machine than the one hooked to my monitor. So BIOS on the other machines does not complain at bootup, I connect broken keyboards to them.

This little network saves more than enough money and annoyance to pay for the router. Way back when I backed up critical data onto 100M Zip disks. That was a lot of thought to decide what was critical and would fit and how much space to leave free for growth. I haven't priced a Zion or Jazz drive or the removable disks lately but the Linksys router was under $80 nearly a year ago. That is about the same price as a 40G hard drive. Whatever drive size drive you have or add to any machine on the network is fast backup.

An external backup drive and media cost more than a 40G hard drive and a router combined. I back up all my data on the other two computers onto one drive on one machine. There is more than enough space to for incremental backup should I ever to do full system backups.

If there is a catastrophic failure of a drive the data is on another drive on another machine. If there is a catastrophic failure of the machine itself the hardest problem is switching the drive to the new machine.

And it saves money directly. Basic cable and DSL has one cost for being in your home with one IP and extra for each additional IP. It is $10 per month locally. If you need one extra IP the router pays for itself in eight months. All the computers on the inside use a single IP.

For the investment in a router and maybe some ethernet cards you have one of the strongest firewalls around. You keep your old machines productive. You have backup storage better and cheaper than any add-on equipment.

And bragging rights? Priceless.

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