KR100687746B1 - Method and apparatus for preventing collision of address - Google Patents

Abstract

The present invention relates to an apparatus and a method for preventing an address conflict, wherein the apparatus for preventing an address conflict in an address management server that allocates N fixed addresses, based on a header of a packet received using a promiscuous mode A receiving unit for receiving the packet when the packet includes a neighbor request (NS) message; A uniqueness determining unit which determines whether or not N fixed addresses coincide with addresses to be included in the received NAVER request (NS) message; And a collision notification unit for transmitting a NAVER Declaration (NA) message indicating that an address to be used is duplicated if an address not yet allocated among N fixed addresses matches. Thus, stateless address auto-allocation scheme prevents collisions between various mobile terminals and home appliances.

Address conflict prevention, address assignment

Description

Method and apparatus for preventing collision of address

1 is a block diagram of an apparatus for preventing an address conflict.

2 is a block diagram of an IPv6 network environment to which an address dispatch prevention scheme is applied between stateful address autoconfiguration and stateless address autoconfiguration in an IPv6 network of the present invention.

3 is a flowchart for implementing the address conflict prevention of the present invention.

The present invention prevents the possibility of address conflict in the automatic address allocation scheme that enables network communication by automatically generating an available address when the system is available, even if the user does not set an address in advance on the interface using the network. The present invention relates to an address collision avoidance apparatus and method.

Conventionally, any system (hereinafter referred to as A system) on one link is configured to always be assigned a fixed address among stateful address auto-assignment schemes, and the other system (hereinafter referred to as system B) is assigned an address by an arbitrary address auto-assignment scheme. If it is set, when system B is activated and system A is assigned an address that it is supposed to be assigned, system A attempts to assign its address from the address assignment server when the system is activated, but it is already assigned by the uniqueness check before assignment. There was a problem that the allocation failed because the interface address of the B system is duplicated.

In order to solve the above problems, the present invention provides a stateless address autoconfiguration scheme and a stateless address autoconfiguration scheme simultaneously and additionally stateless based in an IPv6 network environment. This is to avoid the possibility of an address conflict that may occur when manually assigning an arbitrary address instead of an automatic address allocation scheme.

In one preferred embodiment of the present invention, the address collision avoidance apparatus is an apparatus for preventing address collision in an address management server that allocates N fixed addresses, and a packet received using a PROMISCUOUS mode. A receiver configured to receive the packet when the packet includes a neighbor request (NS) message confirming whether an address is used based on a header of the packet; A uniqueness determination unit that determines whether or not the addresses to be used included in the received NAVER request (NS) message match the N fixed addresses; And a collision notification unit for transmitting a NAVER Declaration (NA) message indicating that the address to be used is duplicated if an address not yet allocated among the N fixed addresses and the address to be used match.

In addition, the uniqueness determination unit of the address collision avoidance device determines whether the address to be included in the received NAVER request (NS) message and the address that is not yet assigned among the N fixed addresses.

In another preferred embodiment of the present invention, the address collision prevention method is a method for preventing address collision in an address management server that allocates N fixed addresses, and is received using a PROMISCUOS mode. Receiving the packet when the packet includes a neighbor request (NS) message confirming whether an address is used based on a header of the packet; A uniqueness determining step of determining whether or not the addresses to be used included in the received NAVER request (NS) message match the N fixed addresses; And transmitting a neighbor declaration (NA) message indicating that the desired address is duplicated if there is an address not yet allocated among the N fixed addresses and an address matching the desired address. do.

In addition, the uniqueness determination step of the address collision prevention method determines whether the address to be used included in the received NAVER request (NS) message matches an address not yet allocated among the N fixed addresses.

There is a possibility of an address dispatching as follows. One system (hereinafter referred to as System A) is configured to always be assigned to a fixed address among state-based address auto-assignment schemes on one link, and the other system (hereinafter referred to as System B) is configured to be assigned addresses using an arbitrary address auto-assignment scheme. Assume that there is.

In this situation, if system A is not active, the address it is supposed to be assigned does not matter if any system is assigned before system A is activated. This is because the existing uniqueness check is only performed on the address of the active network interface, that is, the assigned address.

In this state, system B is activated and system A can be assigned an address. In this state, system A is activated and attempts to assign its own address from the address assignment server, but the assignment fails because the uniqueness check before assigning duplicates the interface address of system B already assigned.

System A is always configured to be serviced through a fixed address, so it cannot be assigned to another address. Therefore, system A cannot be assigned a network address and cannot be connected to the network.

In addition, even if system B is configured manually from the user, rather than any address auto-assignment method, this address may be an address to be assigned by the state-based address auto-allocation scheme. In this case, too, if system A is manually addressed first and then system A is activated, the address conflicts and system A cannot connect to the network.

The present invention proposes a scheme for preventing address conflicts by preventing other systems from allocating addresses to be set by the address allocation server, that is, addresses that have not yet been assigned but need to be allocated in the future. Allows an address to be assigned to system A normally.

Address autoconfiguration techniques include manual configuration, stateful address autoconfiguration, and stateless address autoconfiguration.

Manual configuration is a method in which an administrator or a user manually inputs an address to be used by a user. When using a server for an external service, a manual configuration is often used when the system needs to have the same address even if the system is changed.

State-based address auto-allocation scheme is provided in the existing IPv4 network environment. There is a separate server (eg DHCP server) that assigns an address, and the system receives an appropriate address from the address-allocation system.

In other words, an arbitrary address management server pre-sets information on a system to which an address is assigned, and receives an address using information set on the server when the corresponding system is activated.

The state-based address auto-allocation scheme consists of a server that manages the address to be assigned using DHCP (Dynamic Host Configuration Protocol) and a client existing in the system to which the address is assigned.

If the system to be assigned an address from this server is activated while the server is running, the client that exists in the system sets the network information of the system by obtaining the address and other information to be assigned to the system from the server.

Stateful address auto-allocation schemes include fixed address assignment schemes, which are always assigned static addresses and information, and dynamic address assignment schemes, which dynamically allocate addresses within the address range managed by the server.

When set to the fixed address allocation scheme, the system always receives only fixed addresses. When set to the dynamic address allocation scheme, the system assigns an unassigned address within the set address. In the state-based address auto-allocation scheme, a normal address is assigned only when the server that assigns the address is always running and configured to assign the address properly.

Stateless address auto-allocation scheme is a new technology unique to IPv6 that is not provided in existing IPv4 network environment. Unlike the state-based address auto-allocation scheme, the stateless address auto-assignment scheme is a method in which a terminal generates its own IPv6 address without a separate address management system. Mac address) to generate the address.

In other words, play and plug technology is a technique of generating an address using a predefined address generation technique and then assigning the generated address through address uniqueness checking. This technique is especially useful when the network equipment is flexible, such as home network environment or mobile environment.

In an IPv6 network environment, when assigning an IPv6 address for an interface, whether it is assigned manually, by stateful auto-allocation, or by stateless auto-allocation, it is always the address assigned to the interface that is unique on its network. Always check the address you are using and assign it only if it is unique.

The process of checking whether the address to be assigned is already in use by another system must be performed. This process confirms the uniqueness of the address to be assigned. This process is defined by a technique called duplicate address detection as an address uniqueness check.

However, in a general network environment, only hosts with potential for duplication can receive NS messages, but the DHCP server of the present invention accepts all packets in order to receive NS messages that are not delivered to the promiscuous. If the packet includes the NS message based on the header of the received packet using the mode, the packet is received.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the same elements among the drawings are denoted by the same reference numerals and symbols as much as possible even though they are shown in different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a block diagram of an apparatus for preventing an address conflict.

In one preferred embodiment of the present invention, the address collision avoidance apparatus 100 includes a receiver 110, a uniqueness determiner 120, and a collision notification unit 130.

The receiver 110 receives the packet when the packet includes a neighbor request (NS) message based on a header of the packet received using the PROMISCUOUS mode.

The uniqueness determiner 120 determines whether an address to be used in the neighbor request (NS) message received by the receiver 110 and an address not yet allocated among the N fixed addresses match.

The uniqueness determining unit 120 only determines whether the N static addresses match only the unassigned addresses, but the allocated addresses are duplicated by the host using the assigned address. Because forwarding a message, if the DHCP server sends a duplicate address message up to this point, there may be added confusion due to the duplicate message. Therefore, the uniqueness determination unit 120 increases the efficiency of the inspection by determining whether only the address to be assigned is unique.

The collision notification unit 130, if there is an address that is not yet assigned among the N fixed addresses and an address that matches the address included in the NS message, the neighbor declaration indicating that the address to be used is duplicated ( NA) Send a message.

2 is a block diagram of an IPv6 network environment to which an address dispatch prevention scheme is applied between stateful address autoconfiguration and stateless address autoconfiguration in an IPv6 network of the present invention.

The configuration diagram of FIG. 2 shows a host 210 (hereinafter referred to as a DHCP server) in which a router 200 which is a boundary of another link or site and a server that performs state-based address auto-assignment function, is not yet activated but is activated. Afterward, the host server 220 is configured to receive a fixed address from the DHCP server 210, and a host 230 newly connected to the current network link to receive an address through an arbitrary address auto-allocation scheme.

Each bold arrow indicates the flow of RA (S1), NS (S2), NA (S3) messages shown in the legend.

A Router Advertisement (RA) message is a message that routers deliver to the systems within the link network information, such as default gateways, PMTUs, sites, or global prefixes, that are needed for the systems in the links that they manage to communicate with the off-link systems. .

The NS (Neighbor Solicitation) message is a message generated by the host to use as its address, and transmitted to the corresponding systems including the address in the link to check whether the systems in the link are in use. At this time, it is not delivered to all systems, but only to systems with an interface ID that matches the least significant 24 bits of the generated address.

The NA (Neighbor Advertisement) message is a message sent to all the systems in the link, meaning that if the system that received the NS message is already in use, if the address included in the NS message is already in use, do not use it. . That is, if the system that sent the NS message receives the NA message within a certain time, the address created for use should not be assigned to the system.

When the host 230 is connected to the link, the host 230 generates a link address and a site or a global address to use when the host 230 generates an address by using an arbitrary address auto-allocation scheme.

Here, the link address is an address used in a single network, mainly for management and internal communication purposes, and a global address is used for data communication with an external IPv6 network, and all are generated by an IP address auto-allocation scheme. .

After creating an address to use, it constructs an NS message and passes it to the systems in the link to check its uniqueness.

Even if the host 230 is set manually instead of an automatic address allocation scheme, the NS 230 constructs an NS message for uniqueness checking before allocating the set address from the user and delivers it to the systems in the link.

In the existing IPv6 network environment, even if the DHCP server is running, no check is made unless there is a conflict with the address assigned to the interface of the host running the server.

Therefore, if the host 220 is configured to receive the same address from the DHCP server as the host 230 and is not yet activated, the host 230 determines that the host 230 intends to use the unique address in the existing network. Could use

However, in the scheme proposed in the present invention, the host in which the DHCP server is operating receives all NS messages and compares them with addresses to be allocated to the host interface in advance to prevent collisions.

The DHCP server has address information to be assigned to each system managed by the DHCP server. For example, {system A information (the MAC address of the system): additional information such as an address to be assigned, an effective time of the address, a host name, and the like} Manage addresses in DHCP configuration file format. The DHCP server has additional information on whether the server has assigned an address by setting a flag when the DHCP server has assigned an address.

Managed address Assignment Information Flags xxx: xxx :: xx  1 (assignment) xxx: xoo :: xx  0 (unallocated)

That is, in one preferred embodiment of the present invention, the DHCP server receives all packets using a PROMISCUOUS mode, which accepts all packets in order to receive NS messages that are not delivered to it.

The host 210 then selects only that the message type is NS and compares the address in the NS message with the unassigned address through the table. It obtains the address information in the received NS message and compares it with the addresses to be assigned one by one. If there is the same address, it is set as the address to be assigned in the future.

The host 230 receives the NA message and does not assign the generated address by accepting that the address is already in use.

In this case, even if the host 220 is activated later than the host 230, the host 210 may securely assign an address to be used by the host 220 in advance and prevent the other host from using the host 220.

3 is a flowchart for implementing the address conflict prevention of the present invention.

As a preferred embodiment of the present invention, a server (eg, a station that performs a fixed address allocation function among a host 300 and a state-based address auto-assignment scheme that are newly connected to a network and assigned an address through a stateless address auto-assignment scheme It is a flowchart for preventing an address conflict between a host 310 in which a DHCP server) is operating.

However, this is an embodiment of the present invention, it should be noted that the substitution, change within the equivalent range.

The start of address assignment begins with the host 300 connected to a network link. The connected host 300 generates an address to be allocated, whether using an automatic address allocation scheme or manually assigning an address of an interface connected to the network.

The host 300 generates a neighbor request (NS) message including an address to be allocated to check whether the address to be assigned is unique within the network link (S301).

If the packet includes a neighbor request (NS) message based on the header of the received packet using the PROMISCUOUS mode, the packet is received (S311).

In operation S312 and S313, a comparison is made between whether an address to be used included in the received NAVER request message matches an address not yet allocated among the N fixed addresses.

If there is an address not yet allocated among the N fixed addresses and an address that matches the address to be used, a neighbor declaration (NA) message indicating that the address to be used is duplicated is transmitted (S314 and S315). . When the host 300 connected to the network link receives the NA message, it determines that the address to be used is already in use and does not allocate an address (S303).

If the address that is not yet allocated among the N fixed addresses and the desired address do not match, the host 300 connected to the network link does not receive the NA message within a predetermined time, and in this case, the host 300 ) Assigns an address to be used to the interface (S302).

The invention can also be embodied as computer readable code on a computer readable recording medium. Computer-readable recording media include all kinds of recording devices that store data that can be read by a computer system. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, which are also implemented in the form of carrier waves (for example, transmission over the Internet). It also includes. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

The best embodiments have been disclosed in the drawings and specification above. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

The present invention may occur when the state-based address auto-allocation scheme and the stateless address auto-allocation scheme are simultaneously provided in an IPv6 network environment, and additionally, when an arbitrary address is manually assigned instead of the stateless address auto-allocation scheme. This prevents the possibility of an address conflict.

Through the apparatus and method of address collision avoidance of the present invention, it is possible to prevent collisions when connecting various mobile terminals and home appliances through a stateless address automatic allocation scheme, and through a fixed address allocation scheme among stateful address automatic allocation schemes. Network connection can be easily achieved by preventing collision even when the network connection of the system that needs to assign a fixed address to the control server or service server.

It is not limited to how the system is activated and whether or not the address is managed by the state-based server, and prevents duplicate assignment of addresses to other systems in the uniqueness check step, thereby enabling more stable net operation.

In addition, the present invention performs the uniqueness determination of only the addresses scheduled to be assigned among the addresses managed by the state-based server, thereby reducing the congestion of the message transmission and increasing the efficiency of the inspection.

Claims (6)

A device for preventing address conflicts in an address management server that allocates N static addresses. A receiver configured to receive the packet when the packet includes a neighbor request (NS) message for confirming whether an address is used, based on a header of the packet received using a PROMISCUOUS mode; A uniqueness determination unit that determines whether or not the addresses to be used included in the received NAVER request (NS) message match the N fixed addresses; And a collision notification unit for transmitting a NAVER Declaration (NA) message indicating that the address to be used is duplicated if an address not yet allocated among the N fixed addresses and the address to be used match. Address conflict prevention device characterized in that. The method of claim 1, And the address management server is a DHCP server. The method of claim 1, wherein the uniqueness determination unit And determining whether an address to be used included in the received NAVER request message matches an address not yet allocated among the N fixed addresses. A method for preventing address conflicts in an address management server that allocates N static addresses. Receiving the packet when the packet includes a neighbor request (NS) message confirming whether an address is used based on a header of the received packet using a PROMISCUOS mode; A uniqueness determining step of determining whether or not the addresses to be used included in the received NAVER request (NS) message match the N fixed addresses; And Transmitting a neighbor declaration (NA) message indicating that the desired address is duplicated if there is an address not yet allocated among the N fixed addresses and an address corresponding to the desired address; Address conflict prevention method, characterized in that. The method of claim 4, wherein the address conflict method A method for preventing address collision, characterized in that performed between a host in which a DHCP server, which is in charge of a fixed address assignment function, and a host assigned an address through a stateless address auto-assignment function. The method of claim 4, wherein the determining the uniqueness And determining whether an address to be used included in the received NAVER request message matches an address not yet allocated among the N fixed addresses.

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