1. 先enable Internal的Wireless LAN
2. set security,选WPA2-PSK
3. 由于wlan是bridged with lan interface (lan interface有自己的interface ip,dhcp server, firewall forwarded to wan)
Guest Wireless LAN
1. 先在wifi,建立wlan_guest
2. 先建立一个新的interface wlan_guest
3. Interface wlan_guest建立interface ip address,DHCP server
4. Firewall wlan_guest => wan