Можно отключить бродкасты полностью (TID 10081960 How to disable all broadcast messages from the server.)
Но тогда оповещение администраторов придется настраивать другими методами (SNMP, .....)
Второй вариант, отключить получение бродкастов на рабочих станциях (NW клиентах) редактированием реестра (логинскрипт, ZEN, ...)
TID 10013637 What are the registry Values for NT Client?
Receive Broadcast Messages
Registry Key: HKLM\SOFTWARE\Novell\Broadcast
Registry Value: [dword] Mode
Default Value: 0
Range: 0, 1, 2 (0=All, 1=Server Only, 2=None)
Client Version: Implemented in NT Client versions 4.3 and later
Description: Tells the client which broadcast messages, if any, to receive. You can choose one of the following settings: All (receive all broadcast messages), Server Only (receives broadcast messages sent by the server only), and None (do not receive any broadcast messages).