JP2004015795A - IPv4 MANAGEMENT METHOD AND MANAGEMENT DEVICE IN IPv6 WIRELESS LAN ENVIRONMENT - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication method and a device which make the most use of characteristics of the old wireless LAN network making to coexist the IPv6 and IPv4, supplementing demerit, which the old DSTM (Dual-Stack Transition Mechanism) has. <P>SOLUTION: The method and the device have a step which solves an IP for domain name by a request to an application program, a step to dynamically assign a mobile IPv4 address for an IPv4 communication when that DA (domain address) for requested domain name is a mobile IPv4 address, and a step to return the address after a lease period of the mobile IPv4 address received expires. By this means, the problem of shortage of IP address is solved by introducting the IPv6 in wireless LAN environment. At the same time, effect of offering a wireless LAN environment, which can keep compatibility with the IPv4, is realized. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an IPv4 management method and a management apparatus in an IPv6 wireless LAN environment, which is a next-generation Internet address system, and more particularly to a method for communicating between an IPv6 terminal in an IPv6 wireless LAN network and an external IPv4 terminal. The present invention relates to an IPv4 management method and a management device in an IPv6 wireless LAN environment.
[0002]
[Prior art]
In recent years, wireless LANs have become widespread in conjunction with the rapid spread of mobile communication devices represented by multifunctional mobile phones. The wireless LAN has an advantage that it is hardly subject to space restrictions as compared with the existing wired LAN. In particular, services for consumers have recently been increasing at a rapid pace because they can enjoy the Internet while freely moving without being restricted by network cables.
[0003]
Introducing IPv6, the next-generation Internet addressing scheme, into a wireless LAN environment has been studied in many ways from the perspective of solving the problem of lack of existing IP (IPv4) addresses due to the increase in subscribers, and examination of test services and the like. Have been. However, in such an IPv6 wireless LAN environment, there is a problem that a smooth connection with the IPv4 environment cannot be performed because the addressing method and the protocol itself are different. For this reason, a protocol conversion device such as an IPv4-IPv6 conversion device is required separately.
[0004]
As a conventional technique for connecting IPv6 and IPv4, there is a method of converting a protocol using the above-described IPv4-IPv6 conversion device or the like. However, according to this method, all loads are concentrated on the conversion device, so that network expandability is lacking, and communication is impossible in applications requiring one-to-one communication such as Internet telephones and games.
[0005]
Another conventional technique has a dual stack configuration having both an IPv4 protocol stack and an IPv6 protocol stack, and there is a method in which an IP address always holds an IPv4 address and an IPv6 address. However, there is no problem in configuring the dual stack, but there is a problem that the mobile IPv4 address cannot be used efficiently because the terminal must always have both the mobile IPv6 address and the mobile IPv4 address. . That is, if all terminals statically have the mobile IPv4 address, the mobile IPv4 address is wasted when IPv4 communication with the outside is not performed. Therefore, a method has been proposed that attempts to improve such a problem while using a dual stack. This method is a dual stack conversion method (DSTM).
[0006]
In DSTM, the dual stack is kept as it is, but the mobile IPv4 address is not assigned from the beginning. That is, a terminal is initially configured with a dual stack only, and a terminal is dynamically assigned a mobile IPv4 address from a server only when requesting IPv4 communication on a terminal having a dual stack. After the IPv4 communication is started using the mobile IPv4 address allocated in this way, the terminal performs communication using the IPv4 over IPv6 tunnel formed up to the border router of the IPv6 network.
[0007]
Then, the IPv4 transmission packet is transmitted through this tunnel and arrives at the border router, and then transmitted to the destination address using the existing IPv4 routing. Although the DSTM uses a dual stack, the problem that the IPv4 address is insufficient in the dual stack method can be solved to some extent by a technique of dynamically allocating an IPv4 address.
[0008]
[Problems to be solved by the invention]
However, there is a problem that IPv4 over IPv6 tunneling is required for each of the dual stack terminals and the border router, and the burden that the border router needs to manage the tunneling state is further increased. To solve this problem, a method of dynamically creating a tunnel is conceivable. In this case, it is necessary to create and delete a tunnel each time each dual-stack terminal and the border router perform IPv4 communication. There is a problem that work is burdensome. Further, there is a problem that the end point of every tunnel is one border router.
[0009]
The present invention has been made in view of such a problem, and the present invention complements the above-mentioned disadvantages of the conventional DSTM and maximizes the features of the wireless LAN network while IPv6 and IPv4 coexist. Provide a communication method that makes the most of it. That is, an IPv6 wireless network that can perform IPv4 communication in an IPv6 wireless LAN network without needing to manage state information in a border router serving as a tunnel endpoint and avoiding a load due to adopting tunneling. It is an object to provide an IPv4 management method and a management device in a LAN environment.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an IPv4 management method in an IPv6 wireless LAN environment, wherein an IPv6 terminal arranged in an IPv6 wireless LAN server network has a mobile IPv6 address. Acquiring an internal IPv4 address and an internal IPv4 address, and a destination address (hereinafter referred to as a DA: Destination Address) of a terminal that intends to communicate using the internal IPv4 address is assigned within the IPv6 wireless LAN server network. A determining step of determining whether the mobile IPv4 address is different from the mobile IPv4 address, and if the destination address is a mobile IPv4 address as a result of the determining step, the IPv6 terminal sets the mobile IPv4 address to a dynamic host for IPv4. Characterized in that it comprises the allocation step of dynamically allocated from the formed protocol server.
[0011]
According to a second aspect of the present invention, there is provided the IPv4 management method in the IPv6 wireless LAN environment according to the first aspect, wherein the allocated mobile IPv4 address is a dynamic host configuration protocol for IPv4 when a lease period elapses. The method further includes a return step of dynamically returning to the server.
[0012]
According to a third aspect of the present invention, in the IPv4 management method in the IPv6 wireless LAN environment according to the second aspect, in the returning step, after returning the mobile IPv4 address, the IPv6 terminal sets the mobile IPv6 address and the internal IPv4 address. Is further obtained.
[0013]
According to a fourth aspect of the present invention, in the IPv4 address management method in the IPv6 wireless LAN environment according to the first, second or third aspect, the IPv6 terminal has an IPv4 protocol stack and an IPv6 protocol stack. I do.
[0014]
According to a fifth aspect of the present invention, in the acquiring step of the IPv4 address management method in the IPv6 wireless LAN environment according to any one of the first to fourth aspects, the mobile IPv6 address is arranged at a boundary of the wireless LAN core network. And the internal IPv4 address is transmitted from a dynamic host configuration protocol server.
[0015]
According to a sixth aspect of the present invention, in the acquiring step of the IPv4 address management method in the IPv6 wireless LAN environment according to any one of the first to fifth aspects, the internal IPv4 address is set to the wireless LAN server network and the wireless LAN core. It is a private IPv4 address assigned from another dynamic host configuration protocol server in a link connecting to the network, or a link local IPv4 address assigned by an IPv6 terminal by itself.
[0016]
According to a seventh aspect of the present invention, in the IPv4 management method in the IPv6 wireless LAN environment according to the sixth aspect, the determining step includes an AAAA record in which the IPv6 terminal queries a domain name server in the link for a mobile IPv6 address. Sending a domain name query of type A, and, if the query result indicates that there is no address of the AAAA record type for the domain name, a domain name query of the A record type for querying the mobile IPv4 address is performed. Transmitting to the server.
[0017]
According to an eighth aspect of the present invention, in the method for managing an IPv4 address in an IPv6 wireless LAN environment according to any one of the first to seventh aspects, the allocating step includes the step of using a dynamic host configuration protocol for IPv4 of the IPv6 terminal. Activating a dynamic host configuration protocol client program for IPv4 by a trigger program to request the dynamic host configuration protocol server for IPv4 to allocate a mobile IPv4 address; The method may further include transmitting information on one mobile IPv4 address and an IPv4 basic router address from the address pool to the IPv6 terminal, and receiving the mobile IPv4 address by the IPv6 terminal.
[0018]
According to a ninth aspect of the present invention, in the IPv4 management apparatus in an IPv6 wireless LAN environment, a mobile IPv6 address and an internal IPv4 address for assigning a mobile IPv6 address and an internal IPv4 address to an IPv6 terminal arranged in an IPv6 wireless LAN server network. IPv4 address acquisition means and a judgment for judging whether or not the destination address of a terminal which intends to communicate using the IPv4 address is a mobile IPv4 address different from the internal IPv4 address assigned in the IPv6 wireless LAN server network When the destination address is a mobile IPv4 address as a result of the means and the determining means, the IPv6 terminal dynamically allocates a mobile IPv4 address from the dynamic host configuration protocol server for IPv4 instead of the internal IPv4 address. And a mobile IPv4 address returning means for dynamically returning the mobile IPv4 address to the dynamic host configuration protocol server for IPv4 when the validity period of the mobile IPv4 address expires. I do.
[0019]
According to a tenth aspect of the present invention, there is provided a program for causing a computer to execute each of the steps according to any one of the first to seventh aspects.
[0020]
According to an eleventh aspect of the present invention, there is provided a computer-readable recording medium having a program recorded thereon, wherein the computer is caused to execute each step according to any one of the first to seventh aspects.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0022]
FIG. 1 is a diagram showing an overall configuration of an IPv6 wireless LAN network of the present invention.
Reference numerals 111 and 112 are terminals having a dual stack. The overall wireless LAN network of the present invention includes an IPv6 wireless LAN server network 110 composed of dual stack terminals, an external IPv4 network 120 composed of IPv4 terminals, and an external IPv6 network 130 composed of IPv6 terminals. Each network is connected to a wireless LAN core network 140 composed of a dual stack router 141 and an IPv4 router 142.
[0023]
The dual stack terminal 111 belonging to the IPv6 wireless LAN server network communicates with the external IPv4 terminal 121 through the dual stack router 141 and the IPv4 router 142. Another dual stack terminal 112 belonging to the IPv6 wireless LAN server network communicates with the IPv6 terminal 131 through the IPv6 over IPv4 tunnel 145 formed between the dual stack routers.
[0024]
In the IPv6 wireless LAN environment, the terminal has two types of addresses in the initialization step, a mobile IPv6 address and an internal IPv4 address, and domain name resolution is performed using the internal IPv4 address. If the DA is a mobile IPv4 address as a result of resolving the domain name, the internal IPv4 address already possessed by the terminal is dynamically sent from a Dynamic Host Configuration Protocol (DHCP) server for IPv4. It is dynamically replaced with the acquired mobile IPv4 address. That is, the IPv6 wireless LAN terminal not only communicates with the IPv6 terminal while having both the mobile IPv6 address and the mobile IPv4 address, but also has a new mobile IPv4 address, thereby enabling normal communication with the external IPv4 terminal. Also becomes possible. The mobile IPv4 address is dynamically returned to the DHCP (DHCPv4) server for IPv4 again when all communications with the external IPv4 terminal are completed or a predetermined lease time has elapsed, and the mobile IPv6 address and the internal IPv6 address are again returned. It will have only IPv4 addresses.
[0025]
FIG. 2 is a flowchart illustrating a method in which an IPv6 terminal communicates with an IPv4 terminal using a mobile IPv4 address. In the IPv4 communication method in the IPv6 wireless LAN environment, an initialization step (S210) for preparing an IPv6 terminal to perform the communication method according to the present invention and a step of resolving an IP corresponding to a domain name by a request of an application program (S220). And determining whether the DA for the requested domain name is a mobile IPv4 address (S230). If the result of the determination is that the DA is a mobile IPv4 address, the mobile IPv4 address is changed to communicate with the IPv4 terminal. (S240), and a step of returning the mobile IPv4 address after the lease period of the received mobile IPv4 address has elapsed (S250).
[0026]
In the initialization step (S210) in which the IPv6 terminal prepares for the IPv4 communication in the IPv6 wireless LAN environment of the present invention, each terminal in the IPv6 wireless LAN (all terminals in the IPv6 wireless LAN have a dual stack). ) Obtains two types of addresses, namely, a mobile IPv6 address and an internal IPv4 address.
[0027]
In the step of resolving the IP address corresponding to the domain name in response to the request of the application program (S220), the terminal in the IPv6 wireless LAN uses the internal IPv4 address assigned in the initialization step to set the DNS (Domain Name Server) in the link. ) Sends a query for the domain name. At this time, a domain name query of an AAAA record type for inquiring a mobile IPv6 address is first sent, and if a result indicating that there is no AAAA record type address for the domain name is obtained, an A record type query for a mobile IPv4 address is made Send again. Thus, the IP address requested by the application program is obtained according to the priority of the mobile IPv6 address. When the DA for the requested domain name is a mobile IPv4 address and performs communication through IPv4, in the step of dynamically allocating the mobile IPv4 address (S240), the terminal in the IPv6 wireless LAN uses a DHCPv4 client Is started, and one mobile IPv4 address is dynamically assigned from a DHCPv4 server within the link.
[0028]
Then, in the step (S250) of returning the assigned mobile IPv4 address after the lease period of the assigned mobile IPv4 address has elapsed, the communication with the external IPv4 terminal is completed or the DHCPv4 server returns to the DHCPv4 server after a predetermined time has elapsed. Dynamically return that address. That is, the terminal again has the mobile IPv6 address and the internal IPv4 address.
[0029]
Next, a flow for the dual stack terminal to communicate with the IPv4 terminal of the external IPv4 network will be described with reference to FIGS. 3, 4, 5, and 6. FIG.
FIG. 3 is a configuration diagram illustrating an initialization step in which an IPv6 terminal prepares for IPv4 communication in an IPv6 wireless LAN environment. When the dual stack terminal 311 enters the IPv6 wireless LAN server network 310, it performs an operation to acquire its own IPv6 address and IPv4 address. The dual stack terminal 311 receives a router advertisement message periodically distributed by the dual stack router 320 and acquires a mobile IPv6 address (330).
[0030]
Then, after acquiring the internal IPv4 address, a private IPv4 address is allocated from another DHCPv4 server 340 in the link (350), or an IPv4 address for link local is created and used by itself without receiving information separately. You can also. If the internal IPv4 address is obtained through the private IPv4 address or the link local IPv4 address, the IPv6 wireless LAN terminal can communicate with the outside through IPv6 and communicate with the terminal inside the wireless LAN server network link through IPv4.
[0031]
FIG. 4 is a table showing the types of two types of addresses (IPv4 and IPv6) assigned to an IPv6 terminal or the like in the initialization step and the setting state of the terminal in the initialization step. That is, the mobile IPv6 address is assigned by the router advertisement message as the address of the IPv6 terminal, and the basic router address is obtained by the router advertisement message, but the DNS address is not assigned here because it is unnecessary. The IPv4 address is assigned by an internal address assignment method, and the basic router address and the DNS address are statically assigned in advance.
[0032]
FIG. 5 is a configuration diagram illustrating a step of resolving an IP for a domain name in response to a request of an application program and a step of communicating with an external IPv4 host.
The IPv6 wireless LAN terminal 510 sends a query for the domain name to the DNS 520 in the link (521). At this time, a domain name query of an AAAA record type for inquiring a mobile IPv6 address is first sent, and if a result indicating that there is no AAAA record type address for the domain name is obtained, an A record type query for a mobile IPv4 address is made Repeat the sending step again. Therefore, the mobile IPv6 address is given priority over the mobile IPv4 address, and the IP address is obtained at the request of the application program. The DNS 520 sends a query to the upper DNS 530 along the connection link of the DNS (522, 523).
[0033]
Since the DA obtained for the requested domain name is the mobile IPv4 address, when performing IPv4 communication, the DHCPv4 client is started by the DHCPv4 trigger program of the IPv6 terminal, and the DHCPv4 server 540 sets the mobile IPv4 address. (541).
[0034]
The DHCPv4 server sends one mobile IPv4 address from the IPv4 address pool and a response having information on the IPv4 basic router address for connection with the outside to the wireless LAN terminal. The DHCPv4 trigger program running on the wireless LAN terminal receives this response and assigns this mobile IPv4 address to the interface instead of the internal IPv4 address currently assigned to the wireless LAN terminal. Thereby, when the application program operating on the wireless LAN terminal subsequently communicates with the external IPv4 terminal, it communicates with the newly assigned mobile IPv4 address.
[0035]
FIG. 6 is a diagram showing a table representing types and setting states of an IPv4 address and an IPv6 address after dynamically acquiring a mobile IPv4 address in an IPv6 wireless LAN environment.
Since the mobile IPv4 address is allocated and used only when the application program communicates with the IPv4 terminal on the external network, the wireless LAN network provides the IPv6 communication and efficiently uses the mobile IPv4 address which is an important resource. can do.
[0036]
FIG. 7 is a diagram illustrating an IPv4 address management device in an IPv6 wireless LAN environment in which an IPv6 terminal communicates with an IPv4 terminal using a mobile IPv4 address. The IPv4 address management device includes a mobile IPv6 address and internal IPv4 address allocating unit 710, a determining unit 720, a mobile IPv4 address allocating unit 730, and a mobile IPv4 address returning unit 740.
[0037]
The mobile IPv6 address and internal IPv4 address allocating unit 710 has a function of allocating a mobile IPv6 address and an internal IPv4 address to an IPv6 terminal arranged in an IPv6 wireless LAN server network. Also, the determination unit 720 has a function of determining whether the DA of the terminal that intends to communicate using the IPv4 address is a mobile IPv4 address that is not an internal IPv4 address existing inside the IPv6 wireless LAN server network. ing. Also, the mobile IPv4 address allocating unit 730 has a function of dynamically allocating a mobile IPv4 address to an IPv6 terminal from a DHCPv4 server when the result of the determination by the determining unit 220 indicates that the mobile IPv4 address is a mobile IPv4 address, and substituting the mobile IPv4 address with the internal IPv4 address. Further, the mobile IPv4 address return unit 740 has a function of dynamically returning the mobile IPv4 address to the DHCPv4 server after the lease period of the assigned mobile IPv4 address has elapsed.
[0038]
On the other hand, the above-described embodiment of the present invention can be created by a computer-executable program, and can be realized by a computer that operates the program using a computer-readable recording medium. Computer-readable recording media include magnetic recording media (eg, ROM, floppy disk, hard disk, etc.), optical recording media (eg, CD-ROM, DVD, etc.) and carrier waves (eg, transmission via the Internet). Including various recording media.
[0039]
In the foregoing, the present invention has been described mainly on the preferred embodiments. Those skilled in the art to which the present invention pertains will understand that the present invention can be implemented in modified forms without departing from the essential characteristics of the present invention. Accordingly, the disclosed embodiments are to be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and any differences within the scope of the invention should be construed as being included in the present invention.
[0040]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a wireless LAN environment in which IPv6 is introduced in a wireless LAN environment to solve the problem of shortage of IP addresses and, at the same time, compatibility with IPv4 can be maintained. It becomes. As described above, in recent years, the wireless LAN market has been increasing explosively. This will further accelerate the currently expected depletion of the Mobile IPv4 address space. Therefore, the introduction of IPv6, which is a fundamental solution to the address shortage problem, is an urgent task, but the introduction is expected to increase particularly in a wireless LAN network. However, not all networks can be immediately installed with IPv6, and coexistence with IPv4 is necessary in the transition period.
[0041]
According to the method presented in the present invention, all services currently available are based on IPv6, but if it becomes necessary to communicate over IPv4, the existing IPv4 terminal is obtained by dynamically acquiring and using a mobile IPv4 address. Communication with the user can be performed without any problem.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of an IPv6 wireless LAN network of the present invention.
FIG. 2 is a flowchart illustrating a method of communicating an IPv6 terminal with an IPv4 terminal using a mobile IPv4 address.
FIG. 3 is a configuration diagram illustrating an initialization step for preparing an IPv6 terminal to perform an IPv4 communication method in an IPv6 wireless LAN environment.
FIG. 4 is a table showing types of two types of addresses (IPv4 and IPv6) assigned to an IPv6 wireless LAN terminal in an initialization process and a setting state of the terminal in an initialization stage.
FIG. 5 is a configuration diagram illustrating a step of resolving an IP for a domain name in response to a request of an application program and a step of communicating with an external IPv4 host.
FIG. 6 is a table showing types and setting states of an IPv4 address and an IPv6 address after a mobile IPv4 address is dynamically acquired in an IPv6 wireless LAN environment.
FIG. 7 is a diagram illustrating an IPv4 address management device in an IPv6 wireless LAN environment for an IPv6 terminal to communicate with an IPv4 terminal using a mobile IPv4 address.
[Explanation of symbols]
110 Wireless LAN server network 111, 112, 311 Dual stack terminal 120 IPv4 network 121 IPv4 terminal 130 IPv6 network 131 IPv6 terminal 140 Wireless LAN core network 141, 320 Dual stack router 142 IPv4 router 145 IPv4 tunnel 310 IPv6 wireless LAN server network 340, 540 DHCPv4 server 510 IPv6 wireless LAN terminal 520, 530 DNS (domain name server)
710 Mobile IPv6 address and internal IPv4 address assignment unit 720 Judgment unit 730 Mobile IPv4 address assignment unit 740 Mobile IPv4 address return unit

Claims (11)

An acquiring step in which an IPv6 terminal arranged in an IPv6 wireless LAN server network acquires a mobile IPv6 address and an internal IPv4 address;
A determining step of determining whether a destination address of a terminal that intends to communicate using the internal IPv4 address is a mobile IPv4 address different from an internal IPv4 address allocated inside the IPv6 wireless LAN server network;
If the result of the determination step is that the destination address is a mobile IPv4 address, the IPv6 terminal comprises an assignment step of dynamically assigning a mobile IPv4 address from a dynamic host configuration protocol server for IPv4. An IPv4 management method in an IPv6 wireless LAN environment. The IPv6 of claim 1, further comprising a return step of dynamically returning the assigned mobile IPv4 address to the IPv4 dynamic host configuration protocol server after a lease period has elapsed. IPv4 management method in wireless LAN environment. The IPv4 management in the IPv6 wireless LAN environment according to claim 2, wherein in the returning step, after returning the mobile IPv4 address, the IPv6 terminal further acquires the mobile IPv6 address and the internal IPv4 address. Method. The method according to claim 1, 2 or 3, wherein the IPv6 terminal has an IPv4 protocol stack and an IPv6 protocol stack. The method of claim 1, wherein in the acquiring step, the mobile IPv6 address is allocated from a dual stack router located at a boundary of a wireless LAN core network, and the internal IPv4 address is transmitted from the dynamic host configuration protocol server. Item 5. An IPv4 address management method in an IPv6 wireless LAN environment according to any one of Items 1 to 4. In the acquiring step, the internal IPv4 address is a private IPv4 address assigned by another dynamic host configuration protocol server in a link connecting the wireless LAN server network and the wireless LAN core network, or the IPv6 address is 6. The IPv4 address management method in an IPv6 wireless LAN environment according to claim 1, wherein the terminal is a link-local IPv4 address assigned by the terminal. The determining step includes:
The IPv6 terminal sending a domain name query of an AAAAA record type for querying the mobile IPv6 address to a domain name server in the link;
Transmitting, to the domain name server, a domain name query of an A record type for inquiring the mobile IPv4 address when receiving a result that the address of the AAAA record type does not exist for the domain name as a result of the query; 7. The IPv4 management method according to claim 6, further comprising: The allocating step starts a dynamic host configuration protocol client program for IPv4 by a trigger program for dynamic host configuration protocol for IPv4 stored in the IPv6 terminal, and allocates the mobile IPv4 address to the IPv4 terminal. Requesting a dynamic host configuration protocol server for
The IPv4 dynamic host configuration protocol server transmitting information on one mobile IPv4 address and an IPv4 basic router address from an IPv4 address pool to the IPv6 terminal;
8. The IPv4 address management method in an IPv6 wireless LAN environment according to claim 1, further comprising the step of the IPv6 terminal receiving the mobile IPv4 address. Mobile IPv6 address and internal IPv4 address allocating means for allocating a mobile IPv6 address and an internal IPv4 address to an IPv6 terminal arranged in an IPv6 wireless LAN server network;
Determining means for determining whether a destination address of a terminal that intends to communicate using the IPv4 address is a mobile IPv4 address different from an internal IPv4 address allocated in an IPv6 wireless LAN server network,
When the destination address is a mobile IPv4 address as a result of the determination means, the IPv6 terminal replaces the internal IPv4 address with a mobile IPv4 address dynamically allocated from a dynamic host configuration protocol server for IPv4. ,
Return means for dynamically returning the mobile IPv4 address to the dynamic host configuration protocol server for IPv4 when the validity period of the mobile IPv4 address expires. IPv4 address management device. A program for executing each step according to any one of claims 1 to 8 using a computer. A computer-readable recording medium on which a program for causing a computer to execute the steps according to claim 1 is recorded.

Images