ZyXEL Communications 802.11g ADSL 2+ 4-Port Security Gateway HW-D Series - Manual (Page 435)

P-662H/HW-D Series User’s Guide
Appendix L NetBIOS Filter Commands 435
sys filter netbios
config 3 on This command blocks IPSec NetBIOS packets.
sys filter netbios
config 4 off This command stops NetBIOS commands from initiating calls.