KR100789933B1 - A dad method of ipv6 address auto configuration - Google Patents

Abstract

A DAD(Duplicate Address Detection) method for IPv6 addresses is provided to perform initial access quickly and minimize handover delays due to address allocation time in handover between routers by shortening DAD time in automatic IPv6 address allocation in a mobile communication network. If a mobile terminal, a base station, and a gateway router are connected mutually by wireless(201), the gateway creates an IPv6 interface ID based on the MAC address of the mobile terminal(202). The gateway router compares the created IPv6 interface ID with previously created interface IDs and confirms whether an address collision is generated(203,204). In case the created IPv6 interface ID collides with an existing address, the gateway router sets an I flag, or an interface ID flag which will be contained in the prefix information extension of a router advertisement message, to "1"(205). Then the gateway router selects an arbitrary random number which will not make a collision(207) and allocates the random number as an interface ID for the mobile terminal(208). If the collision confirmation procedures are completed, the gateway router sets the ID flag of the router advertisement message to "1"(209) and notifies the mobile terminal that DAD for the IPv6 interface ID based on the MAC address of the mobile terminal has been completed(210).

Description

Duplicate Address Detection Method for IP Version 6 Address {A DAD Method of IPv6 Address Auto Configuration}

1 is a configuration diagram of an embodiment of a wireless mobile communication network connected to a general IPv6 network;

2 is a flowchart illustrating a duplicate address detection method for an IPv6 address by a gateway router in a wireless mobile communication network according to the present invention;

3 is a diagram illustrating an embodiment of a router advertisement message of FIG. 2;

4 is an exemplary view illustrating a duplicate address detection method for an IPv6 address by a gateway router in a wireless mobile communication network according to the present invention.

* Explanation of symbols for the main parts of the drawings

101: mobile terminal 102: base station

103: gateway router 104: IPv6 network

According to the present invention, an IPv6 (Internet Protocol version 6: "IPv6") address that can be used in the case of a wireless mobile communication network or an IEEE 802.16 based network in which a connection between a wireless access network and a terminal is connected end-to-end Duplicate Address Detection (DAD) method.

In the following example, a duplicate address detection method for an IPv6 address by a gateway router in a wireless mobile communication network will be described as an example, but the present invention is not limited thereto.

Conventional techniques in this field include the Internet Engineering Task Force (hereinafter referred to as the "IETF"), which requests neighbor requests (ICMPv6) messages, which are Internet Control Message Protocol (ICMPv6) messages for the Shard Media Access Network. A duplicate address detection (DAD) is performed with terminals on the same link by using a neighbor solicitation and a neighbor advertisement message. This technology is suitable for an access network using shard media and is not suitable for a mobile communication network or an IEEE 802.16 based network. To this end, WiMAX, which uses a mobile communication network or IEEE 802.16, uses a method of allocating a prefix to a terminal in a node that performs a router function as an address allocation method for the terminal.

In other words, in a wireless mobile communication network or an IEEE 802.16 based network, the communication between the terminal and the terminal can be connected only through the nodes of the network without using the shard media. The use of the IPv6 Duplicate Address Detection (DAD) method proposed by the Internet Engineering Task Force (IETF) has a problem that it takes a long time for a duplicate address detection (DAD) and an overhead in the radio access network. In order to avoid this, in the mobile communication network following the 3rd Generation Partnership Project (3GPP), a duplicate address detection (DAD) is not performed by a method of allocating a prefix for each terminal in a router. However, there is a problem in that one prefix allocation per terminal cannot effectively use an IPv6 address.

The present invention has been proposed to solve the above problems, and detects duplicate addresses in advance by generating an interface ID portion of a terminal predicted before automatic address allocation of the terminal in a node functioning as a router of the network. It is an object of the present invention to provide a duplicate address detection method for an IPv6 address, which is performed through the Router Advertisement message.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

In the method of the present invention for achieving the above object, in the duplicate address detection method for the IPv6 address, the gateway router confirms the radio connection and the IPv6 interface ID (Interface ID) based on the medium access control (MAC) address of the mobile terminal Generating a; Checking, by the gateway router, whether there is an address conflict by comparing the generated IPv6 interface identifier with an IPv6 interface identifier previously managed; As a result of the check, when an address conflict occurs, the first address conflict processing of setting an interface identifier flag to a predetermined identifier, selecting a random number and assigning it as an interface identifier to include in a Router Advertisement message step; A second address conflict processing step of setting an interface identifier flag (I Flag) to a preset identifier if the address does not conflict; And a duplicate address detection completion notification step of notifying the mobile station after indicating that a duplicate address detection (DAD) of an interface identifier is completed in a router advertisement message.

The method may further include generating, by the mobile terminal, a global IPv6 address based on the received Router Advertisement message after receiving the relevant Router Advertisement message. Include.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating an embodiment of a wireless mobile communication network connected to a general IPv6 network.

The wireless mobile communication network includes a mobile terminal 101, a base station 102, a gateway router 103, and an IPv6 network 104.

The mobile terminal 101 refers to a terminal capable of communicating between the mobile terminal 101 through the base station 102 and the gateway router 103 without using shard media and is a node including an IPv6 function.

The base station 102 is connected to the mobile station 101 in a manner other than the shard media access method, and the end-to-end communication with the mobile station 101 is possible. Examples of such a mobile terminal 101 and a base station 102 include a code division multiple access (CDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA) based 3GPP or IEEE 802.16e based mobile terminal. have.

The gateway router 103 is a node connected to a radio access network of such an environment, and is an application system network (ASN: hereinafter referred to as "ASN"), which is referred to as a 3GPP packet gateway support node (GGSN) or an IEEE 802.16e-based WiMAX Forum. Gateway nodes can belong to these nodes. It performs an IPv6 router function and includes an IPv6 router function applicable to a wireless mobile communication access network in the present invention.

The present invention relates to a method for detecting a duplicate address (DAD) of an IPv6 address of a terminal in advance in a gateway router 103 in a wireless mobile communication network composed of a mobile terminal 101, a base station 102, and a gateway router 103.

FIG. 2 is a flowchart illustrating a method for detecting a duplicate address for an IPv6 address by a gateway router in a wireless mobile communication network according to the present invention. FIG. 2 is a diagram illustrating overlapping of an IPv6 address to be automatically assigned by a gateway router in a network structure as shown in FIG. A process of allocating an IPv6 address to a mobile terminal after performing address detection (DAD) in advance is shown.

However, in IPv6, a Router Advertisement message is periodically broadcasted on the same link. However, in the present invention, a Router Advertisement message is defined as a message transmitted to a corresponding terminal only when the terminal completes a wireless connection. This is because the link of the terminal in the wireless mobile communication network uses a property that is set up end-to-end with the base station.

As illustrated in FIG. 2, in the wireless mobile communication network according to the present invention, a method for detecting a duplicate address for an IPv6 address by a gateway router includes first performing a wireless gateway connection between a mobile station, a base station, and a gateway router (201). The router knows that a wireless access connection is established. At this time, the gateway router generates an IPv6 interface ID based on the media access control (MAC) address of the mobile station (202). It checks whether there is an address conflict by comparing the interface IDs of the managed terminals (203, 204).

As a result, if the 64-bit (Bit) IPv6 interface identifier based on the MAC address of the mobile station collides with the existing address, the interface identifier flag to be included in the prefix information extension of the Router Advertisement message (1) is set to (I Flag) (205). Here, the interface identifier flag (I Flag) included in the prefix information extension of the Router Advertisement message is added by the present invention and is set as shown in FIG. 3.

In case of collision, after setting (I Flag) an interface identifier flag (205), an arbitrary random number (Random Number) not to be collided is selected (207), and the interface identifier (Interface) for the MAC of the corresponding mobile terminal. A random number is assigned as an ID to be included in the prefix of the prefix information extension of the router advertisement message (208).

If there is no collision, the interface identifier flag (I Flag) is set to "0" (206).

When the collision check process is completed (204 to 208), the D flag of the Router Advertisement message is set to "1" (209), and the duplicate address of the interface ID based on the MAC address of the UE is set. The mobile station notifies that the detection (DAD) is completed (210). Here, the D flag is a flag representing whether or not DAD completion of a global address including an interface ID based on the MAC address of the UE is completed. Therefore, if the D flag is set and the prefix information extension is not included, the mobile station detects a duplicate address of a global address including an interface ID based on its MAC address. DAD) can be used, and if the IID is set in the prefix information extension, the interface ID according to the MAC address of the UE cannot be used. Can be used to set the global address of the mobile station.

The IPv6 Destination address of the Router Advertisement message is set to the All node multicast address, and is transmitted from the control station to the base stations through the unique data path of the wireless mobile communication network (for example, GTP for 3GPP, GRE for WiMAX), and the path between the base station and the mobile station is through a preset air interface.

The mobile station can receive a related Router Advertisement message and generate (211) a global IPv6 address based on the received Router Advertisement message.

FIG. 3 is an exemplary diagram illustrating the structure of a router advertisement message of FIG. 2 and illustrates a format of a router advertisement message generated by a gateway router for fast duplicate address detection (DAD).

In the present invention, a D flag representing whether a DAD of a global address including a Interface ID based on a MAC address of a UE is included in a Router Advertisement message. If the added D flag is used, but the interface ID based on the MAC address of the UE is in conflict as a result of the duplicated address detection (DAD), the prefix information option field is added to the prefix information option field. The interface identifier flag (I Flag) is added to allocate a random number to the collision of the MAC address of the terminal and in this case, the mobile station.

The Type 301 value of the Router Advertisement message is "134", which indicates that it is a Router Advertisement message.

Code 302 is set to " 0 ", checksum 303 represents ICMP Checksum and cur hop limit 304 is link host. Message transfer hop limit between the packets. The default value is the hop count value of the IPv6 header.

The M flag 305 indicates whether the address of the terminal is used as stateful or stateless, and uses the Dynamic Host Configuration Protocol (DHCP). If set to "1", but set to "0" in the present invention.

O Flag 306 means Other Stateful Configuration and is set to "0" in the present invention, and H Flag 307 is a Router Advertisement message. This indicates whether the node that transmits the Home Agent (HA) function does not participate in the present invention.

The D flag 308 is a flag added by the present invention to indicate whether a duplicate address detection (DAD) for a 64-bit interface ID based on the MAC address of the terminal has been previously made. In other words, if the DAD has been detected by the gateway router in advance, and if there is a conflict as a result of the duplicate address detection (DAD), it indicates whether or not there is a conflict and sets "1" at the time of conflict. Set an alternate address, including Option Extension).

The reserved value 309 is meaningless and is set to "0", and the router lifetime 310 is a value in seconds and the default router available time of the router. The Reachable Time 311 represents a time when one node can access a neighboring node in milliseconds (312), which is not meaningful in the present invention, and is a retransmission timer (312). ) Is a value used to know address resolution and neighbor node state in milliseconds, and has no meaning in the present invention.

The prefix option extension 313 may be used for the purpose of delivering the prefix information of the gateway router to the mobile terminal. In the present invention, when the D flag is set, the mobile terminal as a result is set. In case of having this collided interface ID, it is used to assign a non-collision address to the mobile station.

The type of the prefix option extension is set to "3" (315), and the length (316) is set to "4".

The prefix length 317 is set to " 128 " in the present invention and used to allocate the entire address to the corresponding terminal.

The L flag 318 is set to "1" as a value indicating whether or not prefix information is used on the link, and an A flag 319 is an address auto-location. In the present invention, an R flag 320 indicates an address of a gateway router that has transmitted a Router Advertisement message. In the present invention, this flag is set to "0" to set the address of the terminal.

The I flag 321 is set when the information of the prefix includes the recommended interface ID for the mobile terminal.

Reserved 322 is set to " 0 ", Valid Lifetime 323 is the Time value for which this Prefix is useful over the Link, and the preferred Lifetime ( Preferred lifetime (324) is an effective time of an address generated from a prefix, which is a value in seconds, and indicates a valid time of an address that can be used by an actual terminal in the present invention, and is reserved (325) "0 ", Prefix 326 represents the prefix of the router, in the present invention, the address of the terminal in the case of address conflict due to duplicate address detection (DAD) 64-bit prefix (Prefix) ) And a 64-bit random number.

4 illustrates an example of a method for detecting a duplicate address for an IPv6 address by a gateway router in a wireless mobile communication network according to the present invention, and is an example of IPv6 address allocation and duplicate address detection (DAD) in mobile WiMAX. Indicates.

First, the mobile station establishes a radio link with the base station (401), and the mobile station transmits an SBC-REQ (SBC-REQ) MAC message for the basic capability request of the mobile station to the base station (402). In operation 403, the base station transmits the terminal capability negotiation request response, which is a response thereto, to the base station by including the MAC address of the terminal in the terminal capability negotiation request message and performing the gateway router function (404). In step 405, the base station transmits an SBC-RSP (SS Basic Capability Response) message to the mobile station.

The mobile station performs a user authentication and authentication process for the terminal (406), and if the authentication is successful, sends a REG-Request (REG-REQ: Registration Request) message to the base station (407), and the base station transmits the terminal registration request to the ASN. In response to the gateway (408), the ASN gateway sends the terminal registration request response message to the base station by inserting IPv6-enabled information as a response (409), and the base station sends a response to the REG-response (REG-RSP: Registration Response). The message is sent to the mobile terminal (410).

After transmitting the registration request response message of the mobile station, the ASN gateway executes a duplicate address detection (DAD) for the mobile station identifier (ID) by the procedure of FIG. 2, and simultaneously establishes a connection for data transmission in the mobile station. 412 is executed.

After the data connection is established, a transport connection is created between the mobile station and the base station, and a data path is established between the base station and the ASN gateway to include a duplicate address detection (DAD) result performed by the ASN gateway. A Router Advertisement message is transmitted through the path (413, 414).

Subsequently, the mobile station assigns an automatic address by interface ID according to a flag bit included in a Router Advertisement message or uses an address of a terminal set by an ASN gateway. ) Can be used as a care of address (CoA) of mobile IPv6 (415).

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form. Since this process can be easily carried out by those skilled in the art will not be described in more detail.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

As described above, the present invention can reduce the time required for the duplicate address detection (DAD) when the IPv6 automatic address allocation is performed in the wireless mobile communication network via the router even when the terminal and the terminal do not use shard media. Not only is this faster, but the handover delay caused by address allocation time during handover between routers can be reduced.

Claims (7)

In the duplicate address detection method for IPv6 address, Checking, by the gateway router, a wireless connection and generating an IPv6 interface ID based on the MAC access address of the mobile station; Checking, by the gateway router, whether there is an address conflict by comparing the generated IPv6 interface identifier with an IPv6 interface identifier previously managed; As a result of the check, when an address conflict occurs, the first address conflict processing of setting an interface identifier flag to a predetermined identifier, selecting a random number and assigning it as an interface identifier to include in a Router Advertisement message step; A second address conflict processing step of setting an interface identifier flag (I Flag) to a preset identifier if the address does not conflict; And Duplicate address detection completion notification step of notifying the mobile station after indicating that a duplicate address detection (DAD) of the interface identifier is completed in a router advertisement message Duplicate address detection method for an IPv6 address comprising a. The method of claim 1, The first address conflict processing step, If the IPv6 interface ID collides with an existing address, an interface identifier flag to be included in the prefix information extension of the router advertisement message is set to a preset identifier, and random random that will not collide. Prefix of the prefix information extension of the Router Advertisement message by selecting a random number and assigning it as an interface ID for the MAC of the mobile station. Duplicate address detection method for an IPv6 address, characterized in that included in. The method of claim 2, The duplicate address detection completion notification step, After confirming that the first and second address conflict processing steps have been completed, a duplicate address detection (DAD) of an interface ID based on a MAC address of the mobile station in a Router Advertisement message is detected. And setting a flag indicating that the data is completed to a predetermined identifier, and then notifying the mobile station of the duplicated address for the IPv6 address. The method of claim 3, wherein A flag indicating that a duplicate address detection (DAD) of an interface ID based on a medium access control (MAC) address of the mobile terminal is completed, Flag (D Flag) is a flag representing whether DAD of the global address including the interface ID based on the medium access control (MAC) address of the mobile terminal is completed. If set, and the prefix information extension is not included, the mobile station detects a duplicate address (DAD) of a global address including an interface ID based on its medium access control (MAC) address. Process, and if the IID is set in the prefix information extension, the interface ID cannot be used due to the MAC address of the UE. Prefix) duplicate address check for IPv6 addresses, characterized in that the address set to the global address (Global) address of the mobile terminal Way. The method of claim 4, wherein The prefix option extension, Duplicate address detection (DAD) of the interface ID (Interface ID) based on the medium access control (MAC) address of the mobile terminal is used for transmitting the prefix information of the gateway router to the mobile terminal. The method for detecting a duplicate address for an IPv6 address according to claim 1, wherein the mobile station is used to assign a non-collision address to the mobile station when the mobile station has a collided interface ID. The method of claim 4, wherein The Router Advertisement message, An IPv6 destination address is set as an all node multicast address, and a control station transmits a base station between base stations through a unique data path of a wireless mobile communication network. The method according to any one of claims 1 to 6, Generating a global IPv6 address based on the received Router Advertisement message after the mobile station receives a related Router Advertisement message; Duplicate address detection method for an IPv6 address further comprising.

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