How can I disable SAMBA broadcasting features?
In Debian at least, you could use the option 'disable netbios = yes' in your smb.conf file. I think this is a better option than edit the init scripts. This way you will not have to edit the init scripts every time they get overwritten by upgrades.
edit your rc/init scripts that launch smbd and nmbd so they don't run nmbd. nmbd is the automatic discovery component of samba. Disabling it will cut down on the traffic.
disable netbios = yes in your config file won't stop the nmbd from running from the init.d script. You need to manually comment out the nmbd options from the script after killing nmbd because nmbd will start again after restarting samba services or a reboot.
You can check if netbios isn't running any more by using the following command:
netstat -an | grep 137 (or 138)
This will show if there are listeners active on your system using the port numbers 137 (netbios name) and 138 (Netbios datagram).