Chapter 10 Install and System Administration for FortiOS 5.0 : VLANs : Troubleshooting VLAN issues : NetBIOS
  
NetBIOS
Computers running Microsoft Windows operating systems that are connected through a network rely on a WINS server to resolve host names to IP addresses. The hosts communicate with the WINS server by using the NetBIOS protocol.
To support this type of network, you need to enable the forwarding of NetBIOS requests to a WINS server. The following example will forward NetBIOS requests on the internal interface for the WINS server located at an IP address of 192.168.111.222.
config system interface
edit internal
set netbios_forward enable
set wins-ip 192.168.111.222
end
These commands apply only in NAT mode. If VDOMs are enabled, these commands are per VDOM. You must set them for each VDOM that has the problem.
See Also
Troubleshooting VLAN issues
Asymmetric routing
Layer-2 and Arp traffic
Forward-domain solution
STP forwarding
Too many VLAN interfaces