Linux Bridge and Snort

["Paul Cook" <pkcook () nwlink com>]

Suggestions please.

Set-up:  

bridging eth0 and eth1 to bridge1
eth0 0.0.0.0
eth1 0.0.0.0
bridge1 0.0.0.0

Interested in monitoring traffic to 192.168.15.14.  Traffic is being
forwarded appropriately thus the bridge is connected appropriately.  

Which interface should snort monitor?

What would be appropriate for the following?
HOME_NET = ?
EXTERNAL_NET = ?

Thanks