@Ggjh Yes, you can.

@agus-andre Given your topology description this simulation should work, but I can't say why it isn't. Why don't you give a try with C54 in AP mode: C54 LAN IP - 192.168.100.11 WR940N virtual server:...

@agus-andre According to your screenshots you have not double, but triple NAT in your local network. In front of the WR940N you have another (ISP provided probably) modem/router, hence the reason not...

@agus-andre In general this can be configured as follows. 1) When the C54 is in router mode (double NAT): if your C54 is with WAN IP address 192.168.5.58 the remote access can be set as follows....

@macmon Like I posted if the power provided by the router's USB port is not enough then this could be one reason for its abnormal behavior. You could check for a 'powered USB hub' on your local...

@macmon Usually such kind of issues are caused by not enough power provided by the router to the USB HDD. If I'm not mistaken the router USB port can provide not more than 500mA power to the USB...