JP2003169071A - Home agent system and home agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein, in the prior art, both MN (Mobile Node) and HA (Home Agent) need a design of the correspondence of various messages and so on to change the accommodation destination HA of the MN to another HA and it is difficult to specify the accommodation HA of the MN. <P>SOLUTION: After the HA addresses of HA's 11 and 12 belonging to a home link to be moved are set to HA13 being a movement destination, the path to the home link to be moved is changed in a router 14 from the movement source HA11 and HA12 to the movement destination HA13. Then an existent message of registration and deletion and a binding request message are used to reaccommodate the MN1 in the new HA3. Consequently, the HA can be reaccommodated without collecting or changing the MN's. To the HA, only a function of sending the binding request message to the notice addresses of the registered MN's needs to be added. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a home agent system and a home agent, and more particularly to a home agent (HA) held by a mobile node (MN).
The present invention relates to a home agent system and a home agent that change the accommodation HA in a mobile IPv6 system having a fixed address.

[0002]

2. Description of the Related Art Mobile IP is a conventional IP (Internet
The main purpose is to give mobility to nodes (terminals) of the Protocol (Network) network, and IETF (Internet E
ngineering Task Force) is a terminal mobility management technology that is being standardized. There is IPv6 (IP version 6) as one of the mobile IP protocols. In this mobile IP, a mobile node (MN) holds a home address that is a permanently communicable address and a care-of address used for communication at the destination.
A link including a home address is called a home link (HL) of MN. A router existing on the home link and holding a set of a home address of the MN and a care-of address that is a destination address is called a home agent (HA) of the MN.

When the MN moves on the link, it is always H
Notify A of the destination care-of address (Binding Update Mes
sage). HA notifies from the care-of address (Bindin
g Update Message) and the response message (Binding Acknowledgem
ent Message) to the MN. The HA can also send a notification request (Binding Request Message) to the MN when the HA takes the initiative to request the MN for the movement notification.

[0004] When a correspondent node (CN) of the MN that does not know the movement of the MN communicates with the MN, it communicates with the home address. HA is C
It intercepts and encapsulates the communication from N and transfers it to the care-of address. Upon receiving the communication at the destination, the MN uses the home address as the communication address and sends a reply to the CN. The above is the main function of mobile IP.

By the way, when the traffic of the network is increased and the HA is not sufficiently processed,
If some kind of failure occurs in HA, MN's accommodation H
It is necessary to change A to another HA. In this case, the following procedure is performed to change the accommodation HA of the MN in the conventional Mobile IPv6. First, the source HA
To the MN who wants to move from the MN to the MN that wants to move from the ICMP Mobile Prefix Advertisement message indicating the home link information.
Message) to a notification request (Binding Request Message)
Attach and send.

MN receiving the ICMP Mobile Prefix Advertisement message from HA
Sends an ICMP Home Agent Discovery Request Message to the Mobile IPv6 Home Agent Anycast Address to discover a new HA.
To send. ICMP home agent from MN
The new HA that received the discovery request message sends a response message (ICMP Home Agent Discov
Send an ery Reply Message).

The MN, which has received the above response message from the new HA, registers the current position upon reception of the response message. Therefore, the new HA is notified of the care-of address of the moving destination (Bi
nding Update Message). Upon receiving the notification, the new HA registers the care-of address, which is the current location of the MN, and sends a response message (Bi
nding Acknowledgment Message). The source HA performs the above procedure for all MNs accommodated therein.

[0008]

As described above, in the conventional home agent system based on mobile IP,
To change the accommodation HA of the MN to another HA,
-Both HAs send an ICMP Mobile Prefix Advertisement Message (ICMP Mobile Prefix Adv
ertisement Message), ICMP Home Agent
Discovery Request Message (ICMP Home
It is necessary to design the correspondence between the Agent Discovery Request Message) and the response message (ICMP Home Agent Discovery Reply Message) and the design in which the address of the HA of the registration destination can be dynamically changed.

Conventionally, when replacing the HA, the HA
Since the address of the
When A's MN registration and status monitoring are performed, it is necessary for HA to implement some kind of notification means.
It is difficult to specify A. Furthermore, conventionally, when the accommodation of the HA is changed, it is necessary to stop the mobile registration service of the MN and the communication of the communication partner (CN).

The present invention has been made in view of the above points, and the mobile terminal (MN) is not equipped with a special function, and the mobile registration service of the mobile terminal (MN) is stopped and a communication partner (CN) is used. It is an object of the present invention to provide a home agent system and a home agent that can change the accommodation HA without suspending communication.

[0011]

In order to achieve the above object, a first home agent system of the present invention is a mobile terminal, a first home agent that accommodates a destination address of the mobile terminal, and an accommodation change. A second home agent in a home agent system including the above-mentioned second home agent and a router existing between the first and second home agents, wherein the home agent address held by the mobile terminal is fixed. In the setting means for setting the HA address of the first home agent to the router and the router, the route between the mobile terminal and the first home agent is changed to the route between the mobile terminal and the second home agent. And a moving end registered in the first home agent from the first home agent. The sending means for sending the binding request message to the care-of address and the mobile terminal receiving the binding request message send the binding update message to the HA address, and the binding update message is changed by the route changing means. It is configured to have a registration means for causing the second home agent to receive the care-of address via the router on the route.

According to the present invention, the existing binding request message and binding update message are used to transfer the home agent accommodating the destination address of the mobile terminal from the first home agent to the second home agent. can do.

In order to achieve the above object, the second home agent system of the present invention comprises a mobile terminal,
A plurality of first home agents accommodating the destination address of the mobile terminal and a plurality of first home links connected corresponding to the plurality of first home agents, and a single second destination of the accommodation change destination. The home agent, the plurality of second home links connected to the second home agent, and the router existing between the first and second home agents are provided, and the address of the home agent held by the mobile terminal is set. In a fixed home agent system, setting means for setting the HA address of the first home agent to the second home agent, and a plurality of first home agents from the mobile terminal to the router via the plurality of first home agents. The route to the home link of
Route changing means for changing the route from the mobile terminal to the plurality of second home links via the single second home agent, and the address of the first home link from the first home agent as the home address Have, first
From the first home agent to the mobile terminal whose care-of address is registered in the home agent, and from the mobile terminal receiving the binding request message to the HA.
And a registration unit for transmitting the binding update message to the address, causing the second home agent to receive the binding update message via the router through the route changed by the route changing unit, and registering the care-of address. It is what

According to the present invention, the existing binding request message and binding update message are used to make the home agent accommodating the destination address of the mobile terminal a single second home agent from a plurality of first home agents. Can be transferred to a home agent.

In the third home agent system of the present invention, the second home agent, which has registered the care-of address by the registration means, has the response message transmission means for transmitting the response message to the mobile terminal via the router. , The mobile terminal and the second home agent are
It is characterized by having a means for authenticating the binding update message and the response message, respectively.
According to the present invention, the home agent registration information can be protected from being destroyed by a malicious node.

Further, to achieve the above object, the home agent of the present invention comprises a sending means for sending a binding request message to a registered care-of address of a mobile terminal, and a reply message after registration of the care-of address to a router. It has a response message transmitting means for transmitting to the mobile terminal via.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of a first embodiment of a home agent system according to the present invention.
The present embodiment is a mobile terminal (mobile node) M
N1, a home agent HA2 accommodating the destination address (care-of address), a home agent HA3 as an accommodation change destination, a router (Router) 4 existing between HA2 and HA3, and a communication partner of MN1 And CN5 which is

As an operation setting before the move, the maintenance person uses HA2.
Set multiple HA addresses to. As a result, mobile nodes are grouped for each network of the set HA address. In the embodiment of FIG. 1, two HA addresses are set in HA2, and home links 6 and 7 are set accordingly. Also,
HA2 is set as the home agent of MN1 and an address included in home link 7 is set as the home address. As the setting of the router 4, MN1, CN
5, the route to the home link 6 and the home link 7 is set.

Next, in the embodiment of FIG. 1, HA2
The procedure for relocating the MN1 accommodated in (1) to the newly installed HA3 will be described.

(I) First, the HA address to be moved to HA3, which is the movement destination, is set. Here, in order to replace the home agent of MN1 belonging to home link 7, the HA address of HA2 belonging to home link 7 is set to H.
Set to A3. When the HA address of HA2 is set in HA3, the home link 8 is set. Home link 7
And the home link 8 have the same prefix length.

(II) Next, the relay router 4 is changed so that the route to the relocated home link 7 is changed from HA2 to HA3 and the transfer is performed to the home link 8.

(III) Next, in the MN having the address included in the prefix range of the home link 7 as the home address, the MN which has registered the care-of address of the moving destination in HA2 is registered from HA2 to the care-of address. A binding request message (Bind
ing Request Message) is sent.

(IV) Upon receipt of this binding request message, MN1 receives the binding
Binding Update Message
Is transmitted to the HA address via the network 9. The relay router 4 transfers the communication addressed to the HA address to the relocation destination HA 3 according to the route changed in (II).

(V) Upon receipt of the binding update message from MN1, HA3 registers the care-of address.

(VI) Next, the HA 3 responds to the received binding update message with the MN
To 1 (Binding Acknowle
Send a dgement Message). This binding response message is passed through the router 4 and the network 9 to the M
Received by N1.

(VII) (II) to (VI)
This is performed for all MNs whose location is registered in A2, that is, a pair of care-of address and home address is registered, and when the transfer of the MN from HA2 to HA3 is completed, The registration of the home link 7 and HA address is deleted, and the procedure ends. The reason for deleting is that the packet becomes unreachable due to the network topology and is not necessary.

As described above, in the present embodiment, all the messages used to transfer the MN1 to the new HA3 are existing registration / deletion messages (that is, binding update messages and binding response messages). And the binding request message can be used, it is not necessary to add the implementation of the conventional mobile prefix advertisement message and the ICMP mobile prefix advertisement message to the MN, and the HA can be replaced without collecting and changing the MN. Can be realized. With respect to the HA, the present embodiment can be realized only by adding the function of transmitting the binding request message to the care-of address of the registered MN.

Further, in the present embodiment, the HA address of MN1 is set to the new HA3 to be relocated, so that the HA address of MN1 is set to H of MN1 even if it is relocated.
The A address is constant, and therefore the HA that is the accommodation destination of MN1
Can be easily specified. In IPv6, MN1 and C
Once the communication is established with N5, the destination of MN1 is registered in CN5, so there is no need to communicate via HA unless the home address of MN1 is changed. )-(VII), MN1 and C
N5 can communicate.

Next, a second embodiment of the present invention will be described. FIG. 2 is a block diagram of the second embodiment of the home agent system according to the present invention. In the present embodiment, the MN 10, which is a mobile terminal (mobile node), the home agent HA 11 of the first movement source and its home link 15, and the home agent H of the second movement source.
A12 and its home link 16, HA11 and HA
This is a configuration including the HA 13 which is the integration destination home agent of 12 and its home links 17 and 18, the router 14, and the network 19.

In this system, as the setting before movement,
HA11 is used for communication to the home link 15 in the router 14,
For the communication to the home link 16, the route to be transferred to each of the HAs 12 is set by the maintenance person. Next, FIG.
In the embodiment of the present invention, a procedure for integrating the contained HAs will be described.

(1) First, the maintenance person is the destination HA1.
3, HAs 11 and 1 belonging to the home link of the movement target
2 HA address is set. To set the home link to the destination HA 13, it is not necessary to set the home link of the integration source HA all at once, and before performing the re-registration process by the procedure from (3) to (7) described later. All you have to do is complete the settings.

(2) Next, for the relay router 14, the route to the home link to be relocated is moved to the source HA 11 or HA.
12 is changed to the destination HA 13 and the communication addressed to the source home links 15 and 16 is changed to be transferred to the home links 17 and 18 of the transfer destination HA 13. It is not necessary to change the route for all home links at once, and the route may be changed when the re-registration process is performed according to the procedures (3) to (7) described later.

(3) Next, from the source HAs 11 and 12 to the MN 10 which has an address included in the prefix range of the home link to be moved as a home address and registers the care-of address in the source HAs 11 and 12. Send a Binding Request Message to the care-of address to prompt re-notification of registration information.

(4) The MN 10, which has received the binding request message from the source HAs 11 and 12, responds with a binding update message (Bi
nding Update Message) to the HA address.

(5) The relay router 14 transfers the communication (Binding Update) addressed to the HA address to the relocation destination HA 13 according to the route information changed by the procedure of (2). As a result, the HA 13 that has received the binding update message from the MN 10 registers the care-of address.

(6) The HA 13 sends a binding response message (Bindin) to the MN 10 as a response to the binding update message after registration of the care-of address.
g Acknowledgment Message).

(7) When the movement of the MN 10 is completed,
The home links 15 and 16 of the source HA 11 and 12 and the registration of the HA address are deleted. The procedure ends when the above-mentioned procedures (2) to (7) are applied to all the source HAs. The second embodiment also has the same features as the first embodiment.

Next, a third embodiment of the present invention will be described. The system configuration of this embodiment is the same as that of FIG. 1 or FIG. 2, and IPsec (IP security protocol) is used.
There is a feature in dealing with. In order to protect the HA registration information from being destroyed by a malicious node, the binding update message (Bind
ing Update Message) and Binding Acknowledgment Message
H (Authentication Header) or ESP (Encap
sulating Security Payload). AH is a method of incorporating user authentication data in IP data, and ESP is a method of IP data encapsulation and tunneling.

When the security association (SA) and the key are fixedly set, it does not matter if the same SA and key are set in the source HA and the destination HA, but via the key exchange protocol. When setting the SA and key, the HA is triggered by the reception of a Binding Update Message.
Becomes the initiator and performs key exchange. The MN retransmits the binding update message after a fixed time in accordance with the regulations. Binding update
When the key exchange is performed with the message as an opportunity, the binding update message until the end of the key exchange is discarded, and after the key exchange is established, the location registration of the MN is performed.

[0040]

As described above, according to the present invention,
Using the existing binding request message and binding update message, the home agent that accommodates the destination address of the mobile terminal
Since the home agent of the above is transferred to the second home agent, the mobile terminal does not need to add the mobile prefix advertisement message and the ICMP mobile prefix advertisement message, which have been required in the past. It is possible to realize accommodation of the home agent without collecting and changing the mobile terminal, and without stopping the mobile registration service of the mobile terminal and stopping the communication of the communication partner.

Further, according to the present invention, the HA address is
Since the source HA address is set to a new HA to be relocated, the HA address is constant even if it is relocated, and thus it becomes easy to identify the home agent to which the mobile terminal is accommodated.

Further, according to the present invention, the home agent accommodating the destination address of the mobile terminal is unified from the plurality of first home agents by using the existing binding request message and binding update message. Can be transferred to the second home agent.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

[Explanation of symbols]

1, 10 Mobile terminal (MN) 2, 3, 11, 12, 13 HA (home agent) 4, 14 Router 5 CN (communication node) 6, 7, 8, 15, 16, 17, 18 Home link

Claims (7)

[Claims] 1. A mobile terminal, a first home agent that accommodates a destination address of the mobile terminal, a second home agent that is a destination of accommodation change, and a first home agent and a first home agent that exist between the first and second home agents. A home agent system in which the address of the home agent held by the mobile terminal is fixed, and setting means for setting the HA address of the first home agent to the second home agent; On the other hand, a route changing unit that changes a route between the mobile terminal and the first home agent to a route between the mobile terminal and the second home agent, and from the first home agent , Binding required to the care-of address of the mobile terminal registered in the first home agent. A sending means for sending a solicitation message, and a binding terminal update message sent from the mobile terminal receiving the binding request message to the HA address, and the binding update message is changed by the path changing means. At the second home agent via the router and registering the care-of address, and using the existing binding request message and binding update message, the mobile terminal The home agent system for accommodating the home agent accommodating the destination address of the above, from the first home agent to the second home agent. 2. The care-of address and HA address registered in the first home agent are deleted after the accommodation transfer from the first home agent to the second home agent is completed. The home agent system according to item 1. 3. The second home agent, which has registered the care-of address by the registration means, has response message transmission means for transmitting a response message to the mobile terminal via the router, and the mobile terminal and the mobile terminal The second home agent is the binding
3. The method according to claim 1, further comprising authentication means for the update message and the response message.
The listed home agent system. 4. A mobile terminal, a plurality of first home agents accommodating a destination address of the mobile terminal, and a plurality of first home links connected corresponding to the plurality of first home agents. , A single second home agent that is the accommodation change destination, a plurality of second home links connected to the second home agent, and a router existing between the first and second home agents A home agent system in which the address of the home agent held by the mobile terminal is fixed, a setting means for setting the HA address of the first home agent in the second home agent, and the router, The route from the mobile terminal to the plurality of first home links via the plurality of first home agents is Route changing means for changing a route from a mobile terminal to a plurality of second home links via a single second home agent; and an address of the first home link from the first home agent As a home address and transmitting means for transmitting a binding request message from the first home agent to the mobile terminal in which the care-of address is registered in the first home agent, and the binding request message is received. Causing the mobile terminal to transmit a binding update message to the HA address, and causing the second home agent to receive the binding update message via the router on the route changed by the route changing means, Register the care-of address Registering means for allowing the home agent accommodating the destination address of the mobile terminal to be transferred from a plurality of the first home agents by using the existing binding request message and binding update message. A home agent system, characterized by accommodating and replacing one of the second home agents. 5. The care-of address and HA address registered in the first home agent are deleted after the accommodation transfer from the first home agent to the second home agent is completed. The home agent system according to item 4. 6. The second home agent, which has registered the care-of address by the registration means, has response message transmission means for transmitting a response message to the mobile terminal via the router, and the mobile terminal and the mobile terminal The second home agent is the binding
6. An updating message and a response message authenticating means are respectively provided.
The listed home agent system. 7. A home agent used in the home agent system according to claim 1, wherein:
A transmission means for transmitting a binding request message to the registered care-of address of the mobile terminal; and a response message transmission means for transmitting a response message to the mobile terminal via the router after registering the care-of address. A featured home agent.