Hi all ;),
I finally solved my problem with pf filtering a dual bridge configuration, I have uploaded to my website the pf.conf file in case anybody wants to check it, maybe it is usefull for somebody in similar situation as me.
www.mariolopez.cx/OpenBSD/pf.conf
If anyone finds any errores or anything that could be enchanced I would appreciate knowing about it.
Thanks for all the feedback. --- Mario Lopez <[EMAIL PROTECTED]>