two nics, same network, different topics

[Tamas MEZEI]

Hi,

I'm having a quite same problem as Al Chane had (two interfaces on the 
same network) but with a completely different situation.

So, the box looks like this: a gigabit 3com card (bge0) attached to a 
switch's span (mirror) port, and a fxp0 card for maintaining the traffic 
metering pc, accessing to Apache etc. Both ifaces have an ip address 
from the same network (x.x.x.3 is fxp0 and x.x.x.156 is the metering 
card), and have different hostnames.

(Actually, this is/was an OpenBSD problem, but I'm trying to move the 
box to FreeBSD due to performance and software support.)

Is it possible to route all the packets coming out of the box through 
the fxp0 card (I mean, saying "ok, we have a default route, but you, 
silly packet, you're always gonna use fxp0 to go out from the computer, 
and don't try to use bge0")? If it can be accessed via bridging, and if 
bridging doesn't affect the metering possibilities, please tell me.

We're using Netramet and Nemac to get data from the flows. If the mirror 
iface has an ip address, Nemac cannot "poll" (or whatever it's called it 
does) data from Netramet and the bge0 card and saying something like no 
response from x.x.x.3 (it's the fxp0 card). (It's kinda strange, and 
kinda offtopic, but networking related.) If I say, ifconfig bge0 delete, 
it works again.

The metering card has an IP address because tcpdump would complain (no 
IPv4 address) and maybe it affects it's capabilities. (I'm not so sure.)

BTW, if anyone using Netramet, Nemac or other free traffic metering 
software, and would give me a hand, some advices whatever, please tell 
me, I have some questions, but, I think, it's completely offtopic here.

Thanks,

Tamas