JP4568752B2 - Name resolution device, name resolution method, and socket management method - Google Patents

Description

  The present invention relates to a name resolution device, a name resolution method, and a socket management method.

  A name resolution device called a DNS (Domain Name System) server searches for an address of a web server or the like from the name of a web server or the like in a name resolution request transmitted from a personal computer or the like, and performs name resolution including the address By sending a response to a personal computer or the like, the personal computer can access a web server or the like.

  FIG. 4 is a sequence diagram showing the operation of the conventional name resolution apparatus.

  The name resolution device 1a generates the socket SC1 (step S101). The other computer 2 transmits a name resolution request (step D101). If the name resolution device 1 a stores an address corresponding to the name in the name resolution request, the name resolution device 1 a generates a name resolution response including the address and transmits the name resolution response to the computer 2.

  On the other hand, if not stored, the name resolution device 1a generates a name resolution request including the randomly generated transaction ID, the name, and the port number indicating the socket SC1, and transmits it to the name resolution device 3 (step S103). ).

  In response to the name resolution request, the name resolution device 1a receives the name resolution response transmitted from the name resolution device 3 to the port number using the socket SC1 (step S105), and the transaction in the name resolution response. When the transaction IDs composed of the ID and the transaction ID in the name resolution request match, a name resolution response including the address in the name resolution response is generated, and the name resolution response is transmitted to the computer 2 (step S107). ). Thereby, the computer 2 can access a computer (such as a server) having the name by designating the address. Further, the name resolution device 1a stores the name and address in association with each other for the next time.

  The name resolution device 1a may be attacked by the malicious computer 4. This attack is made to allow the computer 2 to access a fake server and steal the credit card number entered by the user of the computer 2.

  For example, the computer 2 transmits a name resolution request again (step D103), and the malicious computer 4 transmits, for example, a fake name resolution response (step E101). Here, the malicious computer 4 sends a large number of fake name resolution responses including a randomly determined transaction ID and a fake server address to the name resolution device 1a addressed to the randomly determined port number. (Step E101).

  Since the malicious computer 4 randomly determines the port number, it is unlikely that this is the correct port number. That is, it is unlikely that the name resolution device 1a receives a fake name resolution response using the socket SC1. However, since the socket SC1 remains generated and the port number remains unchanged, it is not completely received (step S115). Moreover, before that, the name resolution device 1a has transmitted a name resolution request to the name resolution device 3 (step S113), and the transmission of the regular name resolution response is received from the reception of the fake name resolution response (S115). If the transaction IDs of the transaction IDs in the fake name resolution response and the transaction IDs in the name resolution request match with each other (step S117), the fake address in the name resolution response Is generated, and the name resolution response is transmitted to the computer 2 (step S114). Further, the name resolution device 1a stores the fake address.

  FIG. 5 is a sequence diagram showing the operation of another conventional name resolution apparatus.

  The name resolution device 1b is for solving such inconvenience. When the computer 2 transmits a name resolution request (step D201), the name resolution device 1b generates a socket SC1 (step S201).

  When the name resolution device 1b does not store an address corresponding to the name in the name resolution request, the name resolution device 1b generates a name resolution request including the transaction ID, the name, and the port number of the socket SC1, and transmits it to the name resolution device 3. (Step S203).

  The name resolution device 1b receives the name resolution response using the socket SC1 (step S207), discards the socket SC1 (step S209), and transmits the name resolution response to the computer 2 (step S211).

  When the next name resolution request is transmitted (step D211), the name resolution device 1b generates a socket SC2 that is different from the socket SC1 (step S211).

  If the address is not stored, the name resolution device 1b generates a name resolution request including the port number of the socket SC2 different from the port number of the socket SC1, and transmits it to the name resolution device 3 (step S213).

  For example, the malicious computer 4 transmits a fake name resolution response when the socket SC2 exists (step E201). Among them, there may be a name resolution response addressed to the port number of the socket SC1, and if the name resolution response is transmitted when the socket SC1 exists, the name resolution response is sent to the name resolution device 1b. However, since the socket SC2 is different from the socket SC1, it is not actually received.

  Therefore, according to the name resolution device 1b, before the name resolution response addressed to the port number of the socket SC2 is transmitted and the name resolution response is received, the regular name resolution response is received (step S215), and the socket is resolved. SC2 is discarded (step S217), a regular name resolution response is transmitted to the computer 2 (step S219), and the possibility that the regular address is stored in the name resolution device 1b itself can be increased.

The following Non-Patent Document 1 includes a description of reusing sockets (P.5) and a description of randomly generating sockets (P.7).
Joe Stewart GCIH, "DNS Cache Poisoning-The Next Generation", [online], Internet <URL: http: //www.lurhq.com/dnscache.pdf>

  However, since the name resolution device 1b performs socket generation and destruction for each name resolution, a great amount of processing capacity is used for socket generation and destruction.

  On the other hand, since the name resolution device 1a keeps generating the socket and does not discard the socket, there is a high possibility that a fake name resolution response is transmitted to the computer and the fake address is stored in itself.

  The present invention has been made in view of such a problem, and an object of the present invention is to reduce the processing capacity used for creating and destroying a socket and to transmit a fake name resolution response and fake it. An object of the present invention is to provide a name resolution device, a name resolution method, and a socket management method that can reduce the possibility of storing an address.

In order to solve the above-mentioned problem, the present invention of claim 1 includes a name resolution information database in which a computer name and a computer address are stored in association with each other, and a computer that has transmitted a name resolution request including a name. A name resolution request receiving unit that receives the name resolution request and a name resolution response that includes the address of the computer having the name, and transmits the name resolution response to the computer that transmitted the name resolution request. An address search unit that attempts to search the name resolution information database for an address associated with a name in the name resolution request received by the name resolution request reception unit, and the address cannot be retrieved Generated for use in receiving name resolution responses sent from other name resolution devices A name resolution request including a port number indicating a socket existing when the address could not be retrieved, a randomly generated transaction ID, and the name, and the name resolution request is A name resolution request transmission unit to be transmitted to the name resolution device, and a name resolution response transmitted from the other name resolution device to the port number in response to the name resolution request, using the socket, and the name It is determined whether or not the transaction IDs composed of the transaction ID in the resolution response and the transaction ID in the name resolution request match. When it is determined that they match, the address in the name resolution response is transmitted as the name resolution response. And a name resolution response receiving unit provided to the unit.

The present invention of claim 2 is a name resolution information database in which a name of a computer and an address of the computer are stored in association with each other, and a name that receives the name resolution request from a computer that has transmitted the name resolution request including the name. A resolution request receiving unit; a name resolution response including an address of a computer having the name; and a name resolution response transmitting unit that transmits the name resolution response to the computer that transmitted the name resolution request; and the name resolution request reception An address search unit that tries to search the name resolution information database for an address associated with the name in the name resolution request received by the unit, and if the address cannot be searched, transmits from another name resolution device A socket that is created for use in receiving the name resolution response Is generated, a name resolution request including a port number indicating an existing socket, a randomly generated transaction ID, and the name is generated, and the name resolution request is transmitted to the other name resolution device. The name resolution request transmitter and the name resolution response transmitted from the other name resolution device to the port number in response to the name resolution request are received using the socket, and the transaction ID in the name resolution response is received. And the transaction ID consisting of the transaction ID in the name resolution request is determined to match, and if it is determined to match, the name resolution response that gives the address in the name resolution response to the name resolution response transmission unit If it is determined by the receiving unit and the name resolution response receiving unit that the transaction IDs do not match, Discard the socket that is present when it is determined not to match, and solutions with a name resolution device, characterized in that it comprises a socket update unit to generate different socket with the socket.

According to a third aspect of the present invention , the name stored in the name resolution information database is associated with a name in the name resolution request received by the name resolution request receiving unit and an address given to the name resolution response transmitting unit. A resolution information database update unit is provided, and the name resolution device according to claim 1 or 2 is used as a resolution means.
The present invention of claim 4 includes a name resolution information database in which a computer name and an address of the computer are stored in association with each other, and a name that receives the name resolution request from the computer that has transmitted the name resolution request including the name. A resolution request receiving unit; an address searching unit that attempts to search the name resolution information database for an address associated with a name in the name resolution request received by the name resolution request receiving unit; and If not, a port number indicating a socket that is created to receive a name resolution response sent from another name resolution device and that exists when the address could not be retrieved and a random number Generate a name resolution request including the transaction ID generated in the above and the name, and resolve the name A name resolution request transmission unit that transmits a request to the other name resolution device, and a name resolution response transmitted from the other name resolution device to the port number in response to the name resolution request using the socket. A name resolution response receiving unit that receives and determines whether or not a transaction ID consisting of the transaction ID in the name resolution response and the transaction ID in the name resolution request matches, and a transaction by the name resolution response receiving unit When it is determined that the IDs do not match, the name includes a socket update unit that discards a socket that exists when it is determined that the IDs do not match and generates a socket different from the socket The solution device is used as a solution means.
The present invention of claim 5 is a name resolution method performed by a name resolution device, wherein the name resolution device includes a name resolution information database in which a computer name and a computer address are stored in association with each other, In the name resolution method, the name resolution request receiving unit of the name resolution device receives the name resolution request from the computer that has transmitted the name resolution request including the name, and the address search unit of the name resolution device includes the name resolution request A step of trying to retrieve an address associated with a name in the name resolution request from the name resolution information database, and when the name resolution request transmission unit of the name resolution device cannot retrieve the address, A socket created for use in receiving name resolution responses sent from other name resolution devices. When a request cannot be retrieved, a name resolution request including a port number indicating an existing socket, a randomly generated transaction ID, and the name is generated, and the name resolution request is transmitted to the other name resolution device. And a name resolution response receiving unit of the name resolution device receives a name resolution response transmitted from the other name resolution device to the port number in response to the name resolution request using the socket. A step in which the name resolution response receiving unit determines whether transaction IDs of the transaction ID in the name resolution response and the transaction ID in the name resolution request match, and the name resolution response When the receiving unit determines that they match, the address in the name resolution response is changed to the name of the name resolution device. A name resolution method comprising: a step of giving to a resolution response transmission unit; and a step of the name resolution response transmission unit generating a name resolution response including the address and transmitting the name resolution response to the computer Is the solution.
According to a sixth aspect of the present invention, the name resolution information database update unit of the name resolution device uses the name in the name resolution request received by the name resolution request reception unit and the address given to the name resolution response transmission unit. 6. The name resolution method according to claim 5, further comprising the step of storing the name resolution information database in association with each other.
The present invention of claim 7 is a socket management method performed by a name resolution device, wherein the name resolution device includes a name resolution information database in which a computer name and a computer address are stored in association with each other, In the socket management method, the name resolution request receiving unit of the name resolution device receives the name resolution request from the computer that has transmitted the name resolution request including the name, and the address search unit of the name resolution device includes the name resolution request A step of trying to retrieve an address associated with a name in the name resolution request from the name resolution information database, and when the name resolution request transmission unit of the name resolution device cannot retrieve the address, A socket that is generated for use in receiving name resolution responses sent from other name resolution devices. A name resolution request including a port number indicating a socket existing when the address cannot be searched, a randomly generated transaction ID, and the name is generated, and the name resolution request is transmitted to the other name resolution device. And a name resolution response receiving unit of the name resolution device receives the name resolution response transmitted from the other name resolution device to the port number in response to the name resolution request using the socket. And a step of determining whether or not a transaction ID consisting of a transaction ID in the name resolution response and a transaction ID in the name resolution request match each other, and The socket update unit of the device does not match the transaction IDs by the name resolution response receiver Discarding step a socket that is present when it is determined, the socket updating unit, and solutions with a socket management method which comprises the steps of generating a different socket from the socket.

The eighth aspect of the present invention uses the computer program for configuring the name resolution apparatus according to any one of the first to fourth aspects by a computer as a solution means.

The ninth aspect of the present invention uses a computer-readable recording medium in which the computer program according to the eighth aspect is stored as a solving means.

  According to the present invention, it is possible to reduce the processing capacity used for creating and destroying sockets, and to reduce the possibility of sending a fake name resolution response and storing a fake address.

  Hereinafter, a name resolution device, a name resolution method, and a socket management method according to embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the configuration of the name resolution apparatus according to the present embodiment.

  The name resolution device 1 includes a name resolution information database 11 in which the name of another computer such as a web server and the address of the computer are stored in association with each other, and a computer such as a personal computer that has transmitted a name resolution request including the name Name resolution request receiving unit 12 that receives the name resolution request from the server, and generates a name resolution response including the address of the computer having the name, and transmits the name resolution response to the computer that transmitted the name resolution request When it is attempted to search the name resolution information database 11 for an address associated with the name in the name resolution request received by the response transmission unit 13 and the name resolution request reception unit 12, and the address can be retrieved, An address search unit 14 for giving an address to the name resolution response transmission unit 13; A socket generation unit 15 that first generates a socket used to receive a name resolution response transmitted from a name resolution device (not shown), and receives a name resolution request in advance when a randomly generated transaction ID and address cannot be retrieved. A name resolution request including a name in the name resolution request received by the unit 12 and a port number indicating a socket existing when the address cannot be retrieved is generated, and the name resolution request is not illustrated. The name resolution request transmitting unit 16 to be transmitted to the device, and the name resolution response transmitted to the port number from the name resolution device (not shown) in response to the name resolution request is received using the socket, and the name resolution response Transaction ID consisting of the transaction ID in the name and the transaction ID in the name resolution request The name resolution response receiver 17 gives the name resolution response transmitter 13 the address in the name resolution response and the name resolution response receiver 17 resolves the name. Name resolution information database update in which the name in the name resolution request received by the name resolution request receiving unit 12 and the address are associated with each other and stored in the name resolution information database 11 when an address is given to the response transmission unit 13 When it is determined by the unit 18 and the name resolution response receiving unit 17 that the transaction IDs do not match, the socket existing when it is determined that they do not match is discarded, and a socket different from the socket is generated. Socket update unit 19 and transaction ID storage unit 110 in which a transaction ID is stored Prepare.

(Operation of the name resolution device 1 according to the present embodiment)
FIG. 2 is a flowchart showing the operation of the name resolution device 1. FIG. 3 is a sequence diagram showing the operation of the name resolution device 1.

  First, the socket generator 15 of the name resolution device 1 generates a socket SC1 (step S1).

  Next, the name resolution request receiving unit 12 waits for a name resolution request transmitted from another computer 2. If the name resolution request is transmitted (step D1) and the name resolution request receiving unit 12 receives the name resolution request (step S5: YES), the address search unit 14 addresses corresponding to the name in the name resolution request. Is searched from the name resolution information database 11 (step S7). If the address can be searched (step S9: YES), the address search unit 14 gives the address to the name resolution response transmission unit 13, and the name resolution response transmission unit 13 generates a name resolution response including the address. The name resolution response is transmitted to the computer 2 that transmitted the name resolution request (step S11), and the control returns to step S5.

  If the address cannot be retrieved, the name resolution request transmission unit 16 randomly generates a transaction ID, stores the transaction ID in the transaction ID storage unit 110, and when the transaction ID and the address cannot be retrieved. Generating a name resolution request including a name in the name resolution request received by the name resolution request receiving unit 12 and a port number indicating that the address exists when the address cannot be retrieved (here, socket SC1); The name resolution request is transmitted to another name resolution device 3 (step S21).

  The transaction ID is, for example, 16-bit information, and one of about 65000 values that can be expressed by 16 bits is randomly generated.

  The name resolution device 3 is called, for example, a DNS authority server. The name resolution device 3 retrieves the address of the computer having the name from the name in the name resolution request transmitted from the name resolution device 1 and transmits the name resolution response including the address to the name resolution device 1 and the like It is.

  Next, the name resolution response receiver 17 receives the name resolution response transmitted from the name resolution device 3 to the port number in response to the name resolution request using the socket SC1 (step S23).

  Next, the name resolution response receiving unit 17 reads out the transaction ID, that is, the same transaction ID in the name resolution request transmitted to the name resolution device 3 from the transaction ID storage unit 110, and the transaction ID in the name resolution response. It is determined whether or not the transaction IDs composed of the transaction IDs read from the transaction ID storage unit 110 match (step S25). When it is determined that they match (step S25: YES), the name resolution response receiver 17 gives the address in the name resolution response to the name resolution response transmitter 13, and the name resolution response transmitter 13 includes the name including the address. A resolution response is generated, and the name resolution response is transmitted to the computer 2 that has transmitted the name resolution request received by the name resolution request receiving unit 12 prior to the given address (step S27).

  Next, the name resolution response receiving unit 17 gives the address in the name resolution response to the name resolution information database update unit 18, and the name resolution information database update unit 18 prior to the name resolution request when the address is given. The name and the address in the name resolution request received by the receiving unit 12 are associated with each other and stored in the name resolution information database 11 (step S29), and the control returns to step S5.

  When it is determined that the transaction IDs do not match (step S25: NO), the socket update unit 19 discards the socket that exists when it is determined that they do not match (step S31), and is different from the socket. A socket is generated (step S1), and the control moves to step S5.

  The above operation is similarly performed even when a name resolution request is transmitted from a computer other than the computer 2. The above operation is performed in the same manner regardless of the timing at which the name resolution request is transmitted.

  For example, a name resolution request is transmitted from the computer 2 (step D3), and the malicious computer 4 transmits a fake name resolution response (step E51). If there is a name resolution response addressed to the port number of the socket SC1, the name resolution response is received by the name resolution device 1 (step E511).

  However, it is rare that the transaction IDs match, and in many cases, it is determined that they do not match, and the socket existing at that time is discarded (step S31), and a new socket SC2 is created ( Step S1).

For example, the computer 2 sends a name resolution request when the socket SC2 exists (step D5), and the malicious computer 4 sends a fake name resolution response when the socket SC2 exists, for example. (Step E53). Among them, there may be a name resolution response addressed to the port number of the socket SC1, and if the name resolution response is transmitted when the socket SC1 exists, the name resolution response is sent to the name resolution device 1. However, since the socket SC2 is different from the socket SC1, it is not actually received.
Therefore, before the name resolution response addressed to the port number of the socket SC2 is transmitted from the malicious computer 4 and the name resolution response is received, the regular name resolution response can be received (step S23). The response can be transmitted to the computer 2 (step S27), and the possibility that the regular address can be stored in the name resolution device 1 can be increased.

  That is, the name resolution device 1 generates and destroys sockets when it is determined that the transaction IDs do not match. Therefore, after the malicious computer 4 starts sending a fake name resolution response, the transaction is performed. Since there are more cases where the IDs do not match each other, the number of sockets generated and discarded per unit time increases, making it difficult to receive a fake name resolution response. Therefore, after the malicious computer 4 starts to send a fake name resolution response, the possibility of sending a fake name resolution response and storing a fake address can be reduced.

  On the other hand, since the socket is still generated before the malicious computer 4 starts to send a fake name resolution response, it is used for socket generation and destruction as compared with the case where socket generation and destruction are performed for each name resolution. Processing capacity can be reduced.

That is, according to the name resolution device 1, it is possible to reduce the processing capacity used for socket generation and destruction, and to reduce the possibility of sending a fake name resolution response and storing a fake address. A computer program for configuring the name resolution device according to the present embodiment in a computer, or a computer for causing the name resolution device to execute the name resolution method or the socket management method performed by the name resolution device. The program is stored in a computer-readable recording medium such as a semiconductor memory, a magnetic disk, an optical disk, a magneto-optical disk, or a magnetic tape, and distributed as a display, or the computer program is transmitted via a communication network such as the Internet. You may let them.

It is a block diagram which shows the structure of the name resolution apparatus which concerns on this Embodiment. 3 is a flowchart showing the operation of the name resolution device 1. FIG. 4 is a sequence diagram showing an operation of the name resolution device 1. It is a sequence diagram which shows operation | movement of the conventional name resolution apparatus. It is a sequence diagram which shows operation | movement of the other conventional name resolution apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 3 ... Name resolution apparatus 2 ... Computer 4 ... Malicious computer 11 ... Name resolution information database 12 ... Name resolution request receiving part 13 ... Name resolution response transmission part 14 ... Address search part 15 ... Socket generation part 16 ... Name resolution request Transmission unit 17 ... Name resolution response reception unit 18 ... Name resolution information database update unit 19 ... Socket update unit 110 ... Transaction ID storage unit

Claims (9)

A name resolution information database in which computer names and computer addresses are stored in association with each other;
A name resolution request receiving unit that receives the name resolution request from the computer that has transmitted the name resolution request including the name;
A name resolution response transmission unit that generates a name resolution response including the address of the computer having the name, and transmits the name resolution response to the computer that transmitted the name resolution request;
An address search unit that attempts to search the name resolution information database for an address associated with a name in the name resolution request received by the name resolution request reception unit;
If the address cannot be retrieved, a socket that is generated for use in receiving a name resolution response transmitted from another name resolution device and exists when the address cannot be retrieved. A name resolution request transmission unit that generates a name resolution request including a port number to be indicated, a randomly generated transaction ID, and the name, and transmits the name resolution request to the other name resolution device;
In response to the name resolution request, the name resolution response transmitted from the other name resolution device to the port number is received using the socket, and the transaction ID in the name resolution response and the name resolution request It is determined whether or not transaction IDs composed of transaction IDs match, and when it is determined that they match, a name resolution response receiver that gives an address in the name resolution response to the name resolution response transmitter
A name resolution device comprising: A name resolution information database in which computer names and computer addresses are stored in association with each other;
A name resolution request receiving unit that receives the name resolution request from the computer that has transmitted the name resolution request including the name;
A name resolution response transmission unit that generates a name resolution response including the address of the computer having the name, and transmits the name resolution response to the computer that transmitted the name resolution request;
An address searching unit See attempt to search an address associated with the name in the received name resolution request by the name resolution request receiving unit from the name resolution information database,
If the address cannot be retrieved, a socket that is generated for use in receiving a name resolution response transmitted from another name resolution device and exists when the address cannot be retrieved. A name resolution request transmission unit that generates a name resolution request including a port number to be indicated, a randomly generated transaction ID, and the name, and transmits the name resolution request to the other name resolution device;
In response to the name resolution request, the name resolution response transmitted from the other name resolution device to the port number is received using the socket, and the transaction ID in the name resolution response and the name resolution request It is determined whether or not transaction IDs composed of transaction IDs match, and if it is determined that they match, a name resolution response receiving unit that gives an address in the name resolution response to the name resolution response transmitting unit ;
If it is determined that the transaction ID together with pre Symbol name resolution response receiving unit does not match, discard the socket that is present when it is determined not to the match, the socket updating unit for generating a different socket from the socket A name resolution apparatus comprising: and. Name resolution information database updating unit for storing the name in the name resolution request received by the name resolution request receiving unit and the address given to the name resolution response transmitting unit in the name resolution information database in association with each other
The name resolution apparatus according to claim 1, further comprising: A name resolution information database in which computer names and computer addresses are stored in association with each other;
A name resolution request receiving unit that receives the name resolution request from the computer that has transmitted the name resolution request including the name;
An address search unit that attempts to search the name resolution information database for an address associated with a name in the name resolution request received by the name resolution request reception unit;
If the address cannot be retrieved, a socket that is generated for use in receiving a name resolution response transmitted from another name resolution device and exists when the address cannot be retrieved. A name resolution request transmission unit that generates a name resolution request including a port number to be indicated, a randomly generated transaction ID, and the name, and transmits the name resolution request to the other name resolution device;
In response to the name resolution request, the name resolution response transmitted from the other name resolution device to the port number is received using the socket, and the transaction ID in the name resolution response and the name resolution request A name resolution response receiving unit that determines whether or not transaction IDs including transaction IDs match;
A socket updating unit that discards a socket that exists when it is determined that the transaction IDs do not match by the name resolution response receiving unit, and generates a socket different from the socket;
A name resolution device comprising: A name resolution method of name resolution device performs,
The name resolution device includes a name resolution information database in which computer names and computer addresses are stored in association with each other.
The name resolution method is:
A name resolution request receiving unit of the name resolution device receives the name resolution request from a computer that has transmitted a name resolution request including a name ;
An address search unit of the name resolution device tries to search an address associated with a name in the name resolution request from the name resolution information database;
The name resolution request transmission unit of the name resolution device is a socket generated for use in receiving a name resolution response transmitted from another name resolution device when the address cannot be retrieved, and the address Is generated, a name resolution request including a port number indicating an existing socket, a randomly generated transaction ID, and the name is generated, and the name resolution request is transmitted to the other name resolution device . Steps,
A name resolution response reception unit of the name resolution device receives a name resolution response transmitted from the other name resolution device to the port number in response to the name resolution request using the socket;
The step of determining whether or not the name resolution response receiving unit matches a transaction ID composed of a transaction ID in the name resolution response and a transaction ID in the name resolution request;
The name resolution response receiving unit, when it is determined matching the the steps of Ru gives the address of the name resolution in response to the name resolution response transmission portion of the name resolution device,
The name resolution response transmission unit generates a name resolution response including the address, and transmits the name resolution response to the computer ;
A name resolution method characterized by including: The name resolution information database updating unit of the name resolution device associates the name in the name resolution request received by the name resolution request reception unit with the address given to the name resolution response transmission unit, and the name resolution information Step to store in database
The name resolution method according to claim 5, further comprising: A socket management method name resolution device performs,
The name resolution device includes a name resolution information database in which computer names and computer addresses are stored in association with each other.
The socket management method includes:
A name resolution request receiving unit of the name resolution device receives the name resolution request from a computer that has transmitted a name resolution request including a name ;
An address search unit of the name resolution device tries to search an address associated with a name in the name resolution request from the name resolution information database;
The name resolution request transmission unit of the name resolution device is a socket generated for use in receiving a name resolution response transmitted from another name resolution device when the address cannot be retrieved, and the address Is generated, a name resolution request including a port number indicating an existing socket, a randomly generated transaction ID, and the name is generated, and the name resolution request is transmitted to the other name resolution device . Steps,
A name resolution response reception unit of the name resolution device receives a name resolution response transmitted from the other name resolution device to the port number in response to the name resolution request using the socket;
The step of determining whether or not the name resolution response receiving unit matches a transaction ID composed of a transaction ID in the name resolution response and a transaction ID in the name resolution request;
A step of discarding a socket existing when the socket update unit of the name resolution apparatus determines that the transaction IDs do not match by the name resolution response reception unit;
The socket updating unit includes a step of generating a socket different from the socket. It claims 1 to computer program for configuring a computer name resolution device according to any one of the 4. A computer-readable recording medium in which the computer program according to claim 8 is stored.

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