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I have a bunch of embedded devices that I need to flash with a custom OS.

On each device, the boot-loader (U-Boot) has a fixed IP of and on boot it looks for a TFTP server at to install the OS firmware. This is how the devices are sold off the shelf.

Connecting the devices one at a time to the PC with the TFTP Server will take forever to program the 100+ devices. I need to use some network wizardry to connect multiple devices with the same IP to the TFTP PC with IP

Any ideas will be appreciated.

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migrated from Jan 18 '12 at 3:03

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Why on earth was the boot loader on all these devices configured with a static IP instead of using BOOTP or DHCP? Your real issue is that your company is reaping what it's sown, and you now have the opportunity to fix it so it won't bite you again in the future. – jgoldschrafe Jan 18 '12 at 3:10
I totally agree with you - they should have been DHCP. But as I mentioned in the question, this is how the devices are sold off the shelf to consumers - we don't manufacture them. Modifying U-Boot again brings us back to the same time consuming problem of modifying 100+ devices! – tuxGurl Jan 18 '12 at 19:18
@tuxGurl 3catstoomany below suggested manually flashing each device -- My suggestion is you manually fix U-Boot on each device (and on any new ones you deploy). The choice isn't "do it now or implement a hack", it's "Do it now, or do it on 1000 machines a few years from now when the hack takes too much time/effort": Fixing the problem For Reals this time will save you much more effort in the future. (Unless you don't intend to be around for that, in which case think of your successor and how much you like/hate them :) – voretaq7 Jan 19 '12 at 16:17
@voretaq7 Our custom firmware takes care of on going OS updates. It's just the first time load that's the issue. – tuxGurl Jan 20 '12 at 16:06
up vote 4 down vote accepted

If they don't attempt DHCP on startup, the only way is to have lots of ethernet interfaces on a computer (or switch with VLAN support) and NAT each device to its own IP as seen by your machine.

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VLAN support probably wouldn't help much in this case -- and will always be on the same broadcast domain. – jgoldschrafe Jan 18 '12 at 3:08
Right, but you can have a on each VLAN. With each device on its own VLAN, they won't conflict. You can then NAT incoming connections from to have a different source IP depending on which VLAN sub-interface they come in on. – David Schwartz Jan 18 '12 at 3:14
Thanks @DavidSchwartz. Any resources you can point me to to help with VLAN and NAT setup. I would be quite pleased with connecting just 4-5 devices at a time. – tuxGurl Jan 18 '12 at 19:24
What OS do you plan to use? And what hardware do you have? (Ideally, you'd have a Linux or FreeBSD box and a switch that supports VLANs and some kind of trunk between the switch and the UN*X box.) – David Schwartz Jan 18 '12 at 19:46
I plan to use Ubuntu. I don't have a switch but I'm looking for one as we speak. Any recommendations (budget ~$100)? What do I need to setup a trunk between the switch and box? – tuxGurl Jan 18 '12 at 20:42

Go ahead and start flashing one at a time, you would be finished by now if you had started already. I have an 8 port silent switch on my desk and flash switches while doing something else all of the time. I bet you could start one flash and while it ran properly label one and by the time you recorded your inventory info into a workbook the one being flashed would be complete. Remember, the longest journey begins with a five dollar footlong.

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You have a great point. But that only works when you have a finite number of devices to flash. This will be an ongoing process. – tuxGurl Jan 19 '12 at 19:01

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