FLOPPY BASED ROUTER

Why use a router?...

When connecting to the internet most people will use their workstation for the initial connection.
This is fine until you start playing with the setup and when you start adding and replacing various programs or services then you risk exposing your machine to potential security breaches.
Admittedly I'm talking from a Linux perspective here but it applies to any system. The Code Red worm and IIS webserver springs to mind as one instance of misconfiguration that most people would be familiar with.
With a permanent connection such as cable and the likelihood of more than one computer in the household then a small local network becomes a possibility. This then means the workstation has just become a router and will need to be running even without a local user present.
For this situation a dedicated router is a great solution and should protect you from internal configuration errors.

How?...

There are a few ways to do this, you can zip out and buy a new router (such as Linksys) from the swap meet or local dealer - this will set you back a few dollars on the initial purchase, save you some on the power bill and provide some small amusement (new toy syndrome - great isn't it) while you initially set it up.

But ....
If you want lasting entertainment :) and the chance to build a small system of your choice, then you are in luck...
There is a fair chance that the machine you're using now is not your original, somewhere along the line you upgraded and have a spare 486 - perhaps *gasp* a Pentium, languishing unloved somewhere. Alright, perhaps you don't but your neighbour/relative/friend has... No? then grab one from the nature strip during the next council collection.

If it's a 486 and you choose Eigerstein then one 'gotcha may be the available memory, 12 meg is the recommended minimum. The system could possibly be trimmed to run with 8 meg, but obviously 16 meg would be sweetest. Pentium machines are less likely to have this problem.
I understand floppyfw will run with 8 meg - and like Oxygen it also has the 2.4 kernel. Iptables anyone?

Dust it off and throw two network cards in it, okay maybe these aren't lying around so brave the bright lights and visit the swap meet. Second hand ISA's are dirt cheap.
Next we need a floppy based OS installed on it.

Where from?...

The biggest problem with this idea is finding a suitable image; there are too many of them.

I've tried and still use an Eigerstein image, which is part of the LRP project. The attraction of Eigerstein is that it will fit on one floppy, at 1.68 meg. Don't sweat the size as most regular 1.44meg floppies should cope with it. If not there are alternatives

The LEAF sourceforge site has a large collection of similar images from the unsupported to the current Oxygen. This site also has a lot of different packages to expand your base distribution. Thus my comment about a system of your choice

The floppyfw is one that I used at the start and is very close to a small linux distribution in configuration. It's currently in use by a few on the Optus network.

Next, there's the Freesco release which I've never used but has been mentioned by other O@H users, so it's out there.

Another addition to the list is BBIagent I know nothing about this distro however it mentions a minimum req. of only 8 meg RAM and uses the 2.4 kernel, which is an interesting enough combination to warrant investigation. It's certainly worth a look if you only have the standard (?) 8 x 1 meg sticks most 486's supply

Lastly there is the "free for home use" Gnatbox. This requires registration but it's a possible alternative and is easy to set up. It comes with a web based configuration menu so little networking/linux knowledge should be required as it is totally menu driven. Actually, I used this way before I needed to connect to Optus so I'm unsure of its suitability for cable.

    Jan 2002 -- stmok has been in contact to say...

    I've recently installed Gnatbox Light 3.2.3 on a PC I had lying
    around, and it works fine with OPTUS cable. You can even set it to
    block port 113 (Its open by default with a fake response) without any
    problems.
    By default, you'll get a warning that it blocks multi-cast.

Keep in mind that with any of these floppy distributions you can't do too much wrong. You can try them out on your existing machine and you're hard drive and existing OS will stay intact.
If you modify any config files the changes are not made permanent until you write them to the floppy disk. This means that at any time you have two copies, the existing and editable one running on the RAM disk filesystem and the original gzipped file residing on the floppy.
If you fsck things you can reboot from the original floppy or if you want to keep the changes you'll need to physically flip the read/write tab on the floppy disk.

Configuration...

Uh Uh! .. You're on your own here.
With Eigerstein there is a configuration menu which is fairly straight forward for a seasoned linux user, those who are comfortable with networking terminology or anyone wanting a challenge! It is however nothing like the GUI install that the major Linux distributions now provide.
It may be a steep learning curve but your satisfaction at the end of it should be the greater for it. There are active mailing lists available through the LEAF web site where the questions have already been asked and if need be I'll answer any queries related to the Optus side of it.
What you learn on the way you get to take with you too, it's the basics and you'll be able to build on it.
Charles' Eigerstein packages are well documented at his site, and there are the usual HowTo's available.

Connecting...

Okay, just a little hint then :)
With Eigerstein the connection to Optus is made by downloading the dhclient package from the site and configuring the /etc/dhclient.conf file.
The lrcfg config program should autostart once you log in and this will give you access to all the config files necessary. After downloading and installing the dhclient package it can be accessed via the menu system, however with the changes to the Optus network, nothing needs to be entered in the dhcpd fields, the default setting should allow it to autostart.

Along with the above there's the general config to do, cards, interfaces, firewall rules etc and most of these are buried in the network.conf script but you'll need to visit that yourself, it's well commented. So start at menu 1) Network settings and then work your way down the list.
That will be the pattern for most of the configuration, you can hop behind the scenes and treat it as if from the CLI, but the lrcfg program should see it all done.

What else...

If you've ever used the term "box" to describe your computer then you can use it in it's correct sense now.
When it's configured and running to your satisfaction then install the ssh package on it (HowTo at the Eigerstein site) and then reboot into the BIOS and disable the "Notify on all errors" setting in the first (usually) menu by changing it to "none".

The idea is to run headless and no keyboard (nor a hard drive) therefore we need remote access to it via ssh, we also want it to boot through the BIOS POST sequence without halting, it may complain about lacking a signal from the non-existant monitor, for that we can either ignore it or silence it by disconnecting the speaker!
Because we boot from the floppy and the disk is set as write only, we can be secure in the knowledge that if evil hacker does get in then a reboot will refresh all the files with our original and clean version - a full system reinstall with out the head scratching.

It's a minimalist system so it has no ftp client ( Yes -- there is probably a package for one - but it defeats the purpose of this project) no telnet (Alright...!) and if you wanted to you could probably blow away rm, cp et. al. ( with a little fiddling admittedly ) and scp them over on the rare occasion you'll need them.
The point is that we keep it as a minimalist system with very few tools available to potental intruders.
The Operating System resides on a ram disk so any changes require a physical action on your part to allow the write to proceed. It's only your friends you have to worry about now :)

Possibilities...

Lot's .. Here's some..

Hard Disk
Sick of writing to the floppies? Doing a lot of tweaking and floppy writes are too slow? Then put the hard disk back in, It's the perfect use for that massive 40meg harddrive that you had to sneak home all those years ago and you'll run it at 5% capacity - just like the old days Hmmm!
You can isolate the drive after boot up by using a switch in its power lead, I was able to use an old hard drive bay for mine, which will preserve the non-writable file concept. The system only gets confused if you forget to unmount the drive before turning it off, and no I haven't fried my motherboard, and I'd be surprised if it happens now.

Serial Console
Miss all those messages at boot time?
You'll get some of them back if you enable a serial console then set up minicom to run on the internal machine with a null modem cable between the serial ports.
There is more detail regarding this option here but you'll need to ignore some of the information which is specific to the netboot process described there

No hard drive spare? and the floppys or the drive have failed?

A Boot Rom
This has now moved to it's own page, and has been expanded somewhat. In fact it may even prove useful now.