arp issues...but WHY

[J.D. Bronson]

I have a FreeBSD 5.2.1 machine that has dual NICs.
I would expect the following behavior if I placed both NICs
on the same subnet (192.168.1.1 and 192.168.1.2 for example)...

But in this case they are totally unique:

NIC #1 - 10.10.10.1 255.255.255.0
NIC #2 - 192.168.10.1 255.255.255.0
Default gateway: 10.10.10.10

I am using a single SWITCH for all of my connections.

most of my LAN is on the '10' block, but I have a few machines and 1 router
that are on the '192' block.

When I telnet into the freebsd machine from the '10.10.10.5' to the '10' block
I see ARP comments on the console that I dont understand:


arp: 10.10.10.5 is on fxp0 but got reply from 00:10:7b:80:04:40 on fxp1

How is this possible? - the laptop has NO IP on the 192 block at all.
I understand how to shut up these errors using 'sysctl' - but I wanted to 
know why I am seeing them in the first place?

  -JDB