Methods, network address translation (NAT) devices, network nodes and system for allowing identification of a private device in a public network or treating traffic of a private device in a public network. The NAT may allocate a private IPv4 address to the private device, reserve a block of ports on the public IPv4 address for the private device and send an identification of the block of ports to a network node in the public network. The network node of the public network may receive an identification of a block of ports on the public IPv4 address indicating that the block of ports is reserved for the private device and activate a rule for treating traffic of the private device.