configure linux as transparent router/switch or hub?

Hi,

some background: got two PCs 1, 2 with public Internet IPs, one 1G/10G
switch between PCs and the ISP. I'm trying to push near 1Gbit/s through
the 1G/10G switch through one single port (for certain reasons! testing
and demoing). The ~1Gbit/s traffic consists of two streams, each one
from a different PCs.

Hardware switches (at least those we tested) just can not cope with
that as the traffic comes in in microbursts from the PCs and the small
memory buffer in the switch overflows.

If there is only one stream, it works close enough to 1Gbit/s, but then
it's only one PC/stream instead of both. Receiving PC1 stream in dual
NIC PC2 and adding to that PC2's own stream, i.e. aggregating in PC2
and then streaming to the switch port worked. But I had to use NAT plus
port forwarding, so PC1 server is "hidden" with own IP on private
subnet behind the dual NIC PC.

What I'm trying to accomplish is to have both PC1 and PC2 with public
IP, and PC2 aggregating to its eth0 its own stream plus PC1's stream.

Setup:

PC/server1 PC/server2 10G/1G switch
eth0 ----- eth1 eth0 ----- port fibre ------- Internet

with desired from Internet access as

PC/server1: eth0 IP 193.166.42.15
PC/server2: eth0 IP 193.166.42.16, eth1 IP=??

I already tried just enabling IP forwarding on the PC/server2, but that
didn't quite help, PC1 can't be reached, and PC1 reaches only PC2. The
question is how to set up the dual NIC PC so that it functions as a
transparent router/switch? Or actually even just as a hub?

- Jan

JanW wrote:
> I already tried just enabling IP forwarding on the PC/server2, but that
> didn't quite help, PC1 can't be reached, and PC1 reaches only PC2. The
> question is how to set up the dual NIC PC so that it functions as a
> transparent router/switch? Or actually even just as a hub?

Never mind, we found a solution. It was very simple in the end, using
the Linux 'bridge-utils' package.

http://tldp.org/HOWTO/Ethernet-Bridg...r-HOWTO-3.html

- Jan