[Bridge] Man-in-the-middle scenario within vmware - problem

[Patrick Nagel]

Hi there,

I'm trying to set up a man-in-the-middle scenario within a VMWare Workstation 
team, using brctl. What I want is the following:

PC1 eth0 >---LAN-segment-1---< eth0 PCMITM eth1 >---LAN-segment-2---< eth0 PC2

Now I did the following on PCMITM (PC man in the middle):

ifconfig eth0 down
ifconfig eth1 down
brctl addbr lnxbr0
brctl addif lnxbr0 eth0
brctl addif lnxbr0 eth1
ifconfig eth0 0.0.0.0
ifconfig eth1 0.0.0.0
ifconfig lnxbr0 up

All commands exit successfully and I get eth0, eth1 and lnxbr0 listed in 
ifconfig.
brctl show says:

bridge name	bridge id		STP enabled	interfaces
lnxbr0		8000.000c296df055	no		eth1
							eth0

which also seems alright to me.

But now the problem: although PC1 and PC2 are in the same IP subnet (addresses 
192.168.222.1 and 192.168.222.2), a ping doesn't pass the bridge. By 
starting "ping pc2" on PC1 and "ping pc1" on PC2, I ensure that both machines 
are transmitting data frequently, and thus should show up in "brctl 
showmacs", but
brctl showmacs lnxbr0 says:

port no	mac addr		is local?	ageing timer
  1	00:0c:29:6d:f0:55	yes		   0.00
  2	00:0c:29:6d:f0:5f	yes		   0.00
  2	00:0c:29:97:e3:a6	no		   0.14

So there is one NIC missing - that one of PC1.

Does anyone have an explanation? I don't know what could be wrong in my setup, 
I don't even know where to start... Any help is appreciated.

By the way: The LAN segments within VMWare seem to be working. If I give each 
NIC on PCMITM an IP address (with no bridge on PCMITM), I can transfer data 
from PC1 to PCMITM (and vice versa) and from PC2 to PCMITM (and vice versa).

Patrick.

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