If user worries that open port may lower the computer system security, they can enter into NAS lower level and add firewall rule, and limit only specific IP can pass through UDP PORT 1234.
For more operation details, please refer to the following introduction.
Wake on LAN Security Introduction
First, please enter into [Setting System Management> System Console] and turn on SHH.
Then, please download and use Putty software to connect to PN-401.
Please down software at: https://www.putty.org/
After download process completed, please open [putty.exe], and enter NAS IP address at [Host Name Column]; and enter  in Port, then press [Open] to connect.
Then enter [admin] in account column and press [Enter] then enter the password then press [Enter] again.
NOTE: When you enter the password, it won’t show up, after you finish entering, just press [Enter].
After connected, it will display the following information.
First, you have to get the lower layer administrator [pnadmin]’s password, please enter [cat /etc/pdm/pnadmin], then you will know that pnadmin’s password is 709*****.
Switch to pnadmin identity and enter [su pnadmin], then enter the pnadmin password you just get, after finish entering, press [Enter]. If the screen pop up [pnadmin@PowerNAS] information, it means you already switch identity successfully.
Then you have to make sure current fire wall rule first, you can enter [sudo ufw status] to confirm your fire wall rule.
Please note: if the system asks pnadmin password again, just enter the pnadmin password you have.
Then, you have to add fire wall rule, please enter [sudo ufw allow from IP address you have set to any port 1234 proto udp] and press [Enter], when the screen display [Rule added], it means the fire wall rule has been added successfully.
Please note: For the IP address you have set – please enter the IP address you want to approve, and another IP address cannot pass through UDP port 1234 except this one.
After finished adding fire wall rule, please enter [sudo ufw status] to make sure the rule we just added have been added to the system successfully.