Cannot access device over network interface. Now what?

Question

I made a really dumb mistake today.

I bought a network camera a few days ago from some reseller on eBay, and it's running embedded Linux. I'm not sure what I did, but I edited /etc/network/interfaces, rebooted, and now the device is no longer taking an address from DHCP.

There really aren't any other obvious ways to access it. The device has: an Ethernet in and a power in. The board itself is almost entirely unlabeled, so I'm stumped. All I know is that lsusb had returned two unused ports (I'm guessing it would be for a wireless interface over USB, considering it had all the files for wireless, just not an interface) and the flash memory is on-chip. What do I do now? Did I just brick it?

If I did: agh.

I tried a crossover cable; it did not work. Plugged it in, no response. Checked Wireshark and it was a ghosttown, except for me. Here are a couple images:

The area on the underside of the board is the CMOS sensor and lens apparatus. The second board underneath has no connection to the mainboard except for power. I wasn't expecting the CMOS sensor to be so exposed, so when I lifted the top board, I shivered in fear!

Answer 1

2 ideas for you: 1) Look for a "reset to factory defaults" switch or button or anything that can be shorted or pressed :) 2) Ask the seller the name and password of wifi network he used to connect it to, then duplicate it on your router. It's likely that you only killed wired, not wifi interface and old settings might still be there

Answer 2

Well shoot!

With your cross-over cable you could take a computer off your network such that it's only hooked up to your camera. Then run a full ip scan with nmap.

nmap -T4 -A -v 0-255.0-255.0-255.0-255 >> IP_Scan.results

This should scan -every- possible ip and port for notable results. Now this will take a while, but shouldn't be a few weeks like it would be on the real internet,... and I'd highly suggest trying at least these two rational ranges on their own first (there's a middle one, too, but I always forget it,...):

nmap -T4 -A -v 10.0-255.0-255.0-255 >> IP_Scan.results

nmap -T4 -A -v 192.168.0-255.0-255 >> IP_Scan.results

You'll also want to check the self-assigning range of 169.254.0-255.0-255 in case the network interface defaults to such a thing.

I'm not actually positive you need, or even want, to use a crossover cable for this but it makes the most sense to me at time of writing. You probably want to check with two computers that have known IPs first to ensure you're getting results back at all with your setup.

Anyway once the scan is complete, you can check open up the IP_Scan.results (or whatever you've named it) file to see what IPs and ports exist. You should then be able to find out what the IP of the camera is at.

Once you've got one or more IPs, run nmap as root on them to find the MAC address - but you'll probably have to force your computer to be on that same network first. You may need to fix up your laptop/desktop as a router or gateway itself on the same subnet you find existing on the device. This way you can trick both devices into being networked and communicate valid packets; though it might need some further coercion.

Answer 3

Maybe you gave the device a static IP in a different subnet than the one you are looking in. Do the switch LEDs blink when you jack the device in ? If yes, there´s network traffic and you can use a network monitoring tool to sniff out the packets sent by the device, aswell as the subnet it´s broadcasting in.