etc is working.
These were the instructions I followed but no success yet.
Go into Advanced Setup->LAN. Under the " Static IP Lease List" section click add entries, and
enter the MAC address for your NAS and pick an IP within the 192.168.42.xxx range for it.
To enable port forwarding to that IP inside your netowork go into Advanced Setup->NAT and click add. Enter the external/internal port values and correct protocol(s).. There may be multiple ports that your NAS operates over so you need one entry per port (each entry specifies the port number four times).