packet so that the temporary ip address is assigned to the terminal device tr indirectly in the second embodiment the temporary ip address is set and assigned to the terminal device tr directly the general structure of the quarantine network system kns in the second embodiment is basically the same as that in the first embodiment shown in fig1 however the policy management server 10 the switch with authentication function 2 and the terminal device tr have different functional structures and different process contents hereinafter the differences will be described mainly description of the same portions as the first embodiment will be omitted note that the policy management server the switch with authentication function and the terminal device in the second embodiment are discriminated from those in the first embodiment by referring to as a u201c policy management server 10 b u201d a u201c switch with authentication function 2 b u201d and a u201c terminal device trb u201d respectively the switch with authentication function 2 b has a function of setting its port so that the terminal device trb belongs to one of the vlan a through the vlan e in accordance with an instruction from the policy management server 10 b the functions of the table management portion 201 the ip address translation process portion 202 the arp process portion 203 and the ip translation table tl 1 described in the first embodiment are not necessary programs and data are installed in the hard disk drive of the policy management server 10 b for realizing functions of a policy information obtaining portion 1 b 1 a terminal.