Se você configurou o roteamento e o firewall, ative o roteamento de difusão:
Inicie o cmd
as Administrator
e execute:
reg add HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters /v ForwardBroadcasts /t REG_DWORD /d 0x1 /f
reg add HKLM\SYSTEM\CurrentControlSet\Services\RemoteAccess\Parameters\NetbiosGateway /v EnableBroadcast /t REG_DWORD /d 0x1 /f