can arduino uno support 2 ethernet shields?

Hello!

Can arduino uno support 2 ethernet shields?

I haven't tried it yet, but it is possible. I have code here somewhere that allows the ethernet library to switch slave selects on the fly. You would also need to get the ICSP connector to pass through the lower shield to the upper shield, like remove and replace the 6 pin ICSP connector and don't trim off the pins.

But even after all that, I don't know if the Uno has enough memory to do anything of any use once both ethernet shields are initialized.

OK , can I use uno with one ethernet shield and a raspberry pi which has built in ethernet port to do the same things I need to do?

Am I supposed to guess? ;) What is it you want to do?

To listen all the traffic on a TCP/IP and send the data to a server

cristy2007: To listen all the traffic on a TCP/IP and send the data to a server

Not with an Arduino. Get a faster device. The network traffic can outrun the Arduino's SPI bus.

The data is sent from a IP camera that sends the serial code from a product to a server , I guess is not so much data to be processed

That is a good guess, but may not be correct. The camera and server may be able to send/receive packets at a much faster rate than the w5100 can transfer the data over the SPI bus to the Uno. You may miss several packets.

But why use 2 Ethernet interfaces, you can send on the same one you recieve on even though they are receiving/sending to different addresses. Normally the only things that need multiple ethernet interfaces are routers (and associated setups) where you want to separate networks or servers where the total throughput would exceed a single interface.