Building a Floppy-Based Router

by netfreak

     The "broadband revolution" has come and may home/small office Internet
users subscribe to such ISPs as @home, RoadRunner, Qwest, and Telus.  The 
problem with most of these services is the limit on IP addresses give to each
customer.  Instead of forking out an addition to your monthly bill for more
IPs, why not build a simple router?

Hardware

     You'll need at least a 386 computer with an FPU and 12 megs of RAM.  You'll
also need two Ethernet cards.  For compatibility issues, use 3com, Intel, or
NE2k cards.  If you use ISA cards, be sure to record the IO and IRQ addresses.
If you don't know them, visit the manufacturer's home page (most offer MS-DOS
tools for finding the IO/IRQ).  For convenience, use the smallest PC case you
can find.  Your constructed PC should have the following: 386+ w/ FPU, 12+ MB
RAM, 1.44 MB floppy drive, 2 NICs, keyboard, any video card and monitor.  I 
also recommend a slot fan to keep air circulation in the PC.  To connect your
internal machines to the router, attach a hub or switch to the router's
internal NIC.

Software

     You'll need a Windows PC with a floppy drive and Internet access.  Go to:

	www.coyotelinux.com

and download the Coyote Linux Disk Creator.  When you run the program, you'll go
through a series of steps to setup the software.  You can leave the LAN
configuration as it is (unless you want to change the router address).  The next
step is to setup a login for RoadRunner or whatever your ISP is.  The next step
is for the router's Internet connection.  The default settings should work for
most ISPs.  Next, you can enable DHCP service on the router so the machines
on the internal network will be configured automatically through the router.
The next step is telling Coyote what NICs you will be using.  Be sure to 
double-check your settings.  After that, insert a floppy disk and create the
boot disk.

Router Setup

     Now for the fun part.  Boot up the PC with the Coyote disk and when
prompted to login, use "root" with no password.  A configuration menu will pop
up.  First, change the root password.  Next, you can enable remote access to
the router.  Opening telnet access to the outside world isn't recommended so
you can type this line at the command prompt to only allow internal IP access
to port 23:

	ipchains -A input -p tcp -d 0.0.0.0/0 23 -i eth1 -j DENY
     
     If you want to run a web server behind the router, you can use port
forwarding:

	ipmasqadm autofw -A -r tcp 80 80 -h (internal IP of server)

     Now you're all set!  Documentation and FAQs are available at:

	www.coyotelinux.com