Sometimes there may be a need to reset the network parameters of a QNAP NAS without resetting the entire configuration. Such a need might arise after migrating drives and config to a unit with less network interfaces than the original and an IP address might be bound to a higher numbered interface than exists in the new chassis. That IP address would be unusable until it's released from the old hidden interface.
To reset the network configuration you will need to ensure that it is using a DHCP assigned IP address and then SSH into the QNAP and login with your admin username and password then execute the following commands;
cd /etc/init.d
./network.sh reset_to_default
You will temporarily lose connection to the NAS and then the network settings will be reset.