[narf]

I was interested in trying out dd-wrt (and other alternative firmware), but I did not want to experiment with my live setup. So I came up with a great debugging setup.

One problem is network addressing. How to plug in a second router without interfering with the existing one. The answer of course is to use a physically separate network. But then you need at least two other computers to simulate the existing network. I don't have two extra computers to use for this.

Here is what I DO have:

- a bad-ass Linux workstation with a free PCI slot and lots of RAM
- a copy of VMware
- a 4-port network card I picked up at the MIT flea market

I configured vmware with virtual networks that bridge to the actual network hardware. I set up one for each port on the network card. Then I created a virtual machine for each port. I fired them up and plugged the network ports into a dumb hub for testing. Sure enough, the virtual machines can communicate via the real network hardware. One gotcha they don't mention is that you have to:

ifconfig eth1 up

each network interface before it works.

Now I can simulate my network and fully test the router before I try it live. When the router works as desired, I can just swap it out with my production router.

Another gotcha after swapping out routers is that you have to type:

arp -d 192.168.1.1

on each computer (or reboot it) before it sees the new router.

TCP/IP is soooo coool! Thanks, DARPA!