Quick bridging question

[Claus <cniesen@gmx.net>]

On an OpenBSD machine with two network interfaces, A (internal/lan) and B 
(external/internet), where the a bridge between A and B exists, do packets 
that are sent from the local lan to interface A's IP number get routed out 
to the internet via the B network interface?

In other words.  I run an DHCP server on an OpenBSD machine with 
bridging.  The clients of my server send out a broad cast message that the 
OpenBSD machine sees.  It's DHCP server is responding and assigning an IP 
to the client.  My question is does the broad cast message go through the 
bridge, and so leave my local lan?

I don't think I can prevent this via ipf rules as the DHCP server on the 
OpenBSD machine would never see the clients requests.  Note that out rules 
do not work in bridging mode.

Any help and clarification is appreciated.
   Claus