eth1 -> eth2

I have a Linux box with three network interfaces: eth0, eth1, and eth2. I
would like the output of eth1 to acts as an input to eth2. To accomplish, I
simply connected a cable from the eth1 to eth2.

However, when I send traffic from eth1 (using 'tcpreplay -i eth1'), I get
nothing at eth2 (using 'tcpdump -i eth2').

To simplify matters, I brought iptables down (using 'service iptables stop')
but that didn't solve the problem. Does anyone know what else I need to do
to get this simple setup working?

barcaroller wrote:
> I have a Linux box with three network interfaces: eth0, eth1, and eth2. I
> would like the output of eth1 to acts as an input to eth2. To accomplish, I
> simply connected a cable from the eth1 to eth2.
>
> However, when I send traffic from eth1 (using 'tcpreplay -i eth1'), I get
> nothing at eth2 (using 'tcpdump -i eth2').
>
> [snip]

You need to use a crossover cable because you're probably currently
using a straight-through cable. Or connect the two interfaces through a
hub or switch, just like if they were on different machines. Either way
will work.

On Sat, 16 May 2009 13:53:00 -0400, barcaroller wrote:

> I have a Linux box with three network interfaces: eth0, eth1, and eth2.
> I would like the output of eth1 to acts as an input to eth2. To
> accomplish, I simply connected a cable from the eth1 to eth2.

Why?
If you told people exactly what you are attempting to do and something
about the ethernet wiring, you will get a better answer.

Hi,

"barcaroller" <(E-Mail Removed)> écrivait
news:gumulk$2ak$(E-Mail Removed):

>
> I have a Linux box with three network interfaces: eth0, eth1, and
> eth2. I would like the output of eth1 to acts as an input to eth2. To
> accomplish, I simply connected a cable from the eth1 to eth2.
>
> However, when I send traffic from eth1 (using 'tcpreplay -i eth1'), I
> get nothing at eth2 (using 'tcpdump -i eth2').

You are not the first to try a sych loop.

Unfortunataly the kernel know it doesn't need to send the packet throw the
network interface. It 'route' the packets directly thow the IP stack. No in
ou out traffic throw the physical network.

You should try something more subtil.

Regard