Multiple Ethernet ports on the raspberry pi

Just use an USB to Ethernet stick via a powered HUB.

Dont expect any particular level of performance of any of the posibble solutions as you are some what constrained on bandwidth on all the methods explained here and previously.

I'm assuming you are trying to learn some networking skills rather than learning how to connect say an SPI ethernet device to the RPI.?!

Just use an USB to Ethernet stick via a powered HUB.

Dont expect any particular level of performance of any of the posibble solutions as you are some what constrained on bandwidth on all the methods explained here and previously.

I'm assuming you are trying to learn some networking skills rather than learning how to connect say an SPI ethernet device to the RPI.?!

@john - actually the problem was in trying with more than one USB-Ethernet on a HUB or directly on the pi. I did have a powered USB hub off which the USB ethernet was attached. To make them work one has to configure as Roger mentioned. And am working on a concept/project which is to build up a network of Pi's controlled by a master Pi. Essentially 6 pis controlled by a master pi. So the SPI approach would not work for this many PIs too? I understand the limitation of bandwidth with the USB approach. But it is a POC and we will eventually try and customize the PI I think. There is a space crunch too since it needs to be a compact unit. So will be going to the host transfer cable approach which anyway creates a network interface. But is much more compact. One thing I am not yet sure is with these many host transfer cables the power needs of these "powered" cables will be high and so may need a USB powered hub. If that is so, then I may as well use the USB ethernets. Basically trying to avoid another power plug. I already have one big power source to power all these pis - since the 6 pis have a 7" pi display attached too. Same issue with using an ethernet switch - its expensive, bulky, heavy and needs an external power source[where it will consume gobs of power too] - but may get the maximum performance since its not shared on the Pi - at least not all 6 are shared on a Pi then.

I guess as a POC i want to connect them with the best compact way possible. Essentially need to run graphics off of the main pi. So  need a reasonable connection too!

FYI: The route option was proving very flaky in the end with multiple Ethernets. It would NOT just work with more than 2 ethernets. Had to be reconfigured everytime and still.

But I did a simple "fix" - I created a bridge on the master controller linking all the required ethernet interfaces and it works everytime properly. So just in case anyone needs this:

sudo apt-get install bridge-utils - for brctl

sudo brctl addbr br0

sudo brctl br0 eth1 eth2 eth3

ifconfig eth1 0.0.0.0

ifconfig eth2 0.0.0.0

ifconfig eth2 0.0.0.0

sudo ifconfig br0 up

now br0 is the only visible interface and one can use the child pi's to ping the br0 address and it works reliably. Of course this is temporary i.e. it needs to be set up to be persistent across boots in /etc/network/interfaces I think. Will be trying that next. But hopefully this helps anyone else needing this.

Hi Shreesh,

I hope the link to an article I wrote about the Ethernet / Wifi bridging on PI maybe useful for you: Meditech: Creating a Pi Bridge

Enrico

@enrico - Good article. Good pointer. I did not do the iptables step you have. I guess when I set the interfaces addresses to zero, the bridge handles the switching automatically. Interesting exercise could be to see performance difference between these two approaches since the iptables is another software step/jump. But it may be more "correct" in some ways since it uses the Linux routing infrastructure i.e. in the kernel. I think the difference will be there for large volumes of traffic I think if any. Will try your approach and see too. Performance is an issue due to what I need i.e.bridging across 6 interfaces.