Communication with multiple DUT having the same IP address

[vgravel]

Hello,

I need to communicate by TCPIP to 4 DUT at the same time. The tricky part is that those DUTs have the same IP address (but different MAC address).

I'm wondering what would be the best approach?

• Using 4 NICs (network interface controller) and connecting the every DUTs to his own NIC with a cross cable? The problem I see is that those NICs would have to be on the same subnet which might not be a really good idea.
• Communicating using directly the MAC address? Is that possible? Didn't find any example.
• Any other ideas?

Thanks!

Vincent

[Norbert_B]

Vincent,

sharing the same IP address for several devices is "forbidden". You are currently seeing exactly why.

That being said, you have no chance to use TCP to communicate with that devices as TCP (layer 4) is using IP (layer 3) internally. See here and here for more information.

There are, however, some workarounds you can probably use:

IP Spoofing

Gateway

There might be some more, but i think, these are the two most obvious....

Norbert

[Matthew_Kelton]

I have not done this, so do not know what trouble you would run into.  I had developed a serial to Ethernet bridge for a project using the Lantronix XPort.  Out of the box, it should work, but supported custom firmware if I need to change anything.  Basically, the PC will see a serial port and send serial commands.

I found this via Google:

https://www.sparkfun.com/products/9476

It is the same basic idea.  Part of this depends on what you need to do.  If you don't care about speed, and are just telneting into the device and sending some commands, then something like this will work great.  If you are trying to do any kind of heavy traffic communication, it probably won't.

[RTSLVU]

Ran into this problem several years ago...

Our solution was to use multiple routers, one on each device and a hub.

You computer connects to the hub and the WAN side of each router connects to the hub.

Give each router a static IP address on it's WAN

Connect one device to each router's LAN side.

DISABLE any firewalls and set up port forwarding on each router to IP of the device.

Now from the computer and LabView each device will be on the IP address you gave the router's WAN and the router will tack care of the address translation using NAT

It might sound expecive but go to your local Goodwill and you can pick up routers for around $5 each.