W2K Pro on NT4 PDC excessive traffic

W2K PRO sends lots of traffic on network. Watching network with Sniffer shows the stations broadcasting. First how can I stop the broadcasting? Second, some of the PCs are connecting across state and not seeing the PDC\BDC on campus? (Using nbtstatshows this)Do I need a W2K DNS or PDC so the PCs will stop broadcasting? Any help aprreciated