JP5021533B2 - Information processing terminal - Google Patents

Description

  The present invention relates to an information processing terminal.

  When an information processing terminal uses a host name to access a file server or the like connected to another network via the Internet, a DNS (Domain Name System) server on the network sends a name resolution request specifying the host name. And a conversion process (hereinafter referred to as a name resolution process) for acquiring an IP address corresponding to the host name specified by the name resolution request from the DNS server.

  However, if the address of the DNS server is not registered in the information processing terminal, the name resolution process cannot be performed by the DNS server, and the target file server cannot be accessed. Also, the DNS server may be automatically set by DHCP (Dynamic Host Configuration Protocol). However, in an environment where manual setting is required, the user needs to inquire the address of the DNS server from the network administrator and set it correctly on the information processing terminal, which is a burden on users who are unfamiliar with the network. It is.

  Windows Vista (registered trademark) tries to resolve a name by sending a packet to a plurality of users using multicast or broadcast when name resolution processing cannot be performed using a DNS server. There is a restriction that the target file server must be in the same segment as its own terminal.

  Furthermore, when it is desired to use a DNS server in the group and a DNS server outside the group separately, the information processing terminal normally sets a plurality of DNS servers such as a primary DNS server and a secondary DNS server in the DNS setting. And although a secondary DNS server is dependent on mounting of an information processing terminal, it is used only when the primary DNS server is down. Therefore, when the primary DNS server returns a response that the name resolution cannot be performed to the information processing terminal, the secondary DNS server is not inquired. That is, even if a plurality of DNS servers are set, both DNS servers cannot be used properly.

  As a solution to such a problem, a repeater that can select an inquiry destination from a plurality of DNS servers by a domain name is disclosed (see Patent Document 1). In the relay device according to Patent Document 1, based on the virtual domain name stored in association with the IP address of the DNS server, the DNS server is specified when the input domain name matches the virtual domain name.

International Publication W2004 / 045164

  However, in the technique described in Patent Document 1, if there is no relay that stores the domain name and the IP address of the DNS server in association with each other, the DNS server cannot be accessed and name resolution processing can be performed. There is a problem that it is not possible.

  The present invention has been made in view of the above, and is a case where the DNS server address is not set in the own terminal or the DNS server cannot perform name resolution without providing a repeater or the like. Another object of the present invention is to provide an information processing terminal that can increase the probability of name resolution.

  In order to solve the above-described problems and achieve the object, the invention according to claim 1 is a host name associated with an IP address assigned to an information processing terminal on another network transmitted according to the first protocol. A request receiving means for receiving a name resolution request for designating, a name resolution judging means for judging whether or not a host name included in the received name resolution request matches the host name of the terminal, and the name resolution A request transmitting means for transmitting the name resolution request to the information processing terminal according to a second protocol different from the first protocol when the host name included in the request does not match the host name of the own terminal; Response receiving means for receiving from the information processing terminal a name resolution response including an IP address for the name resolution request transmitted according to the second protocol; Characterized in that and a response transmitting means for transmitting the IP address included in the name resolution response to the requesting of the name resolution request.

  The invention according to claim 2 is the response according to claim 1, wherein the response transmission means determines whether or not to transmit an IP address included in the name resolution response received by the response reception means. The apparatus further includes an execution determination unit, and the response transmission unit transmits an IP address according to a determination result by the response execution determination unit.

  According to a third aspect of the present invention, in the invention according to the second aspect, the response execution determining means determines whether the name resolution response to the name resolution request transmitted to the information processing terminal according to the first protocol is based on the presence or absence of the name resolution response. It is characterized by determining whether or not to transmit an IP address by a first determination method for determining whether or not to transmit an address.

  The invention according to claim 4 is the invention according to claim 2, wherein the response execution determination means determines whether or not to transmit an IP address depending on whether or not the name resolution request is received again according to the first protocol. It is characterized by determining whether to transmit an IP address by the second determination method for determining whether or not.

  Further, the invention according to claim 5 is the invention according to claim 2, wherein the response execution determination means determines whether the domain name included in the name resolution request matches the domain name of the own terminal. It is characterized by determining whether or not to transmit an IP address by a third determination method for determining whether or not it is necessary to transmit an address.

Further, the invention according to claim 6 is the invention according to claim 2, wherein the response execution determination means is configured to resolve the name from an IP address included in the name resolution response and an IP address and subnet mask of the terminal itself. Whether the IP address is transmitted by the fourth determination method for determining whether or not the IP address needs to be transmitted depending on whether the information processing terminal that inquires about the IP address and the own terminal are in the same network. It is characterized by determining whether or not.

The invention according to claim 7 is the invention according to any one of claims 3 to 6, wherein the response execution determination unit includes a domain name of an information processing terminal that inquires an IP address for the name resolution request. When the first determination method or the second determination method determines whether or not to transmit an IP address, and the name resolution request does not include the domain name of the information processing terminal that queries the IP address, the third determination method more law, and judging whether there is a need to send IP address.

  According to the present invention, a name resolution request specifying a host name associated with an IP address assigned to an information processing terminal on another network transmitted according to the first protocol is received, and the received name resolution request is received. It is determined whether or not the included host name matches the host name of the own terminal, and if the host name included in the name resolution request does not match the host name of the own terminal, it is different from the first protocol. A name resolution request is transmitted to the information processing terminal according to the second protocol, a name resolution response including an IP address for the name resolution request transmitted according to the second protocol is received, and the name of the IP address included in the received name resolution response By sending the request to the requester of the resolution request, the DNS server address is not set in the own terminal without the provision of a repeater or the like. Even if it is not possible to name resolution in the server, it is possible to increase the probability of name resolution, an effect that.

  Exemplary embodiments of an information processing terminal according to the present invention will be explained below in detail with reference to the accompanying drawings. In the following embodiment, an example in which the information processing terminal according to the present invention is applied to an MFP (Multi Function Peripheral) will be described. However, the present invention can be applied to a personal computer (PC), a portable terminal, etc. as long as it is connected to a network.

(First embodiment)
FIG. 1 is a block diagram illustrating the configuration of the name resolution system according to the first embodiment. The name resolution system according to the present embodiment includes PCs 1 and 2 (106, 101), a DNS server 102, a file server 103, an MFP 104, and a router 105. MFPs 104 provided in an office or the like are connected to a network such as a LAN (Local Area Network) and can communicate with each other within the network. For example, as shown in FIG. 1, the MFP 104 is connected to a file server 103 and PCs 1 and 2 (101, 106), and can send and receive e-mails and transfer files. Further, if the router 105 is used, the MFP 104 can communicate with the PC 2 (101) and the DNS server 102 outside the network.

  In such a name resolution system, for example, when the file server 103 or the PC 1 (106) accesses the PC 2 (101) outside the network by using the host name, the file server 103 or the PC 1 (106) transmits a name resolution request to the DNS server 102 and sends the PC 2 The IP address of (101) must be acquired. Here, the name resolution request specifies a host name associated with an IP address assigned to an information processing terminal (for example, PC2 (101)) on another network. However, if the address of the DNS server 102 is not registered in the file server 103 or PC1 (106), the file server 103 or PC1 (106) cannot transmit a name resolution request to the DNS server 102, and is outside the network. PC2 (101) cannot be accessed. The name resolution system according to the present embodiment does not have a DHCP server that automatically sets the address of the DNS server 102, and the address of the DNS server 102 is registered in the file server 103 and the PC 1 (106). Make it not exist.

  However, in the name resolution system according to the present embodiment, a plurality of information processing terminals (for example, the file server 103) of the same group such as LLMNR (Link-Local Multicast Name Resolution), mDNS (Multicast DNS), and NBT (NetBT). , The name resolution request can be transmitted to the proxy resolver (MFP 104) in accordance with a protocol capable of transmitting the name resolution request to the MFP 104 and the PC1 (106).

  FIG. 2 is a sequence diagram showing a procedure of name resolution processing in the name resolution system according to the present exemplary embodiment. FIG. 3 is a flowchart showing a procedure of name resolution processing by the proxy resolver. First, an outline of name resolution processing by the name resolution system according to the present exemplary embodiment will be described with reference to FIGS. 2 and 3.

  First, the client (for example, the file server 103) sends a name resolution request including the host name “hogehoge?” To the proxy resolver (for example, the MFP 104) according to the protocol P that can send the name resolution request by multicast (or broadcast). Transmit (step S201).

  When the proxy resolver receives the name resolution request including the host name “hogehoge?” Transmitted from the client (step S301), the proxy resolver receives its own host name and the host name “hogehoge?” Included in the received name resolution request. Are matched (step S202, step S302). Here, when the host name of its own matches the host name “hogehoge?” Included in the name resolution request (step S302: Yes), the proxy resolver uses its own IP address as the name resolution request. The message is transmitted to the requesting client (step S303).

  On the other hand, if the own host name and the host name “hogehoge?” Included in the name resolution request do not match (step S302: No), the proxy resolver is used by the requesting client of the name resolution request. The name resolution process is executed by means other than the means (step S203 to step S206, step S304). Here, another means is that the name resolution request is transmitted according to a protocol Q different from the protocol P used by the request source client for transmitting the name resolution request.

  For example, if the IP address of the DNS server is registered in advance, the proxy resolver transmits a name resolution request to the DNS server according to the DNS protocol (step S203). When the name resolution response including the IP address “192.168.1.2” corresponding to the host name “hogehoge?” Included in the name resolution request is received from the DNS server (step S204), the proxy resolver receives the received name resolution response. The included IP address “192.168.1.2” is transmitted to the client that requested the name resolution request.

  When the IP address of the DNS server is not registered, the proxy resolver is a protocol that can send a name resolution request by multicast or broadcast, and sends the name resolution request to other clients according to a protocol Q different from the protocol P. Transmit (step S205, step S206).

  Further, the proxy resolver performs the same means (multicast) as the client before sending the IP address included in the name resolution response received by executing the name resolution process by another means to the requesting client. May be used to execute the name resolution process (steps S207 and S305). Here, the same means means that the name resolution request is transmitted in accordance with the same protocol as the protocol P used by the request source client for transmitting the name resolution request. Then, the proxy resolver determines whether or not a name resolution response including the IP address “192.168.1.2” is received from another client (steps S208 and S306). The proxy resolver transmits the name resolution request by another means only when the name resolution response is not received (step S306: No), and the IP address included in the received name resolution response is changed to the name resolution request. The data is transmitted to the requesting client (steps S209 and S307). In other words, when the name resolution request is transmitted by the same means as the request source client of the name resolution request and the name resolution response is received (step S306: Yes), the request source client of the name resolution request is already a regular response. This is because the IP address is received from the other party, and it is not necessary to transmit the name resolution request by another means and to intentionally transmit the IP address included in the received name resolution response.

  Next, details of name resolution processing by the proxy resolver will be described with reference to FIGS. FIG. 4 is a block diagram illustrating a hardware configuration of the MFP. FIG. 5 is a block diagram showing a functional configuration of the MFP. FIG. 6 is a sequence diagram showing the procedure of name resolution processing by the MFP.

  First, the hardware configuration of the MFP functioning as a proxy resolver will be described with reference to FIG.

  The controller 400 includes a CPU (Central Processing Unit) 401, an NB (North Bridge) 403, a system memory 402, an SB (South Bridge) 404, a local memory 406, an ASIC (Application Specific Integrated Circuit) 405, and an HDD. (Hard Disk Drive) 407, and the NB 403 and the ASIC 405 are connected by an AGP (Accelerated Graphics Port) bus 418.

  The AGP 418 is a bus interface for a graphics accelerator card that has been proposed to speed up graphics processing, and makes the graphics accelerator card faster by directly accessing the system memory 402 with high throughput. .

  The CPU 401 performs overall control of the MFP 104, has a chip set including the NB 403, the system memory 402, and the SB 404, and is connected to other devices via the chip set.

  The NB 403 includes a CPU 401, a system memory 402, an SB 404, an ASIC 405, an Ethernet (registered trademark) interface 412, a USB (Universal Serial Bus) interface 413, an IEEE 1394 (the Institute of Electrical and Electronics Engineers 1394) interface 414, and a Centronics. A bridge for connecting the interface 415, the wireless interface 416, and the external storage medium interface 417, a memory controller that controls read / write to the local memory 406, a PCI (Peripheral Component Interconnect) master, and an AGP target Have.

  The SB 404 is a bridge for connecting the NB 403 to a PCI device and peripheral devices. The SB 404 is connected to the NB 403 via the PCI bus 419. Various interface units 412 to 417 and the like are also connected to the PCI bus.

  An Ethernet (registered trademark) interface 412 is an interface device that connects the MFP 104 according to the present embodiment to a network. The USB interface 413, the IEEE 1394 interface 414, the Centronics interface 415, and the wireless interface 416 are interfaces conforming to the respective standards, and may be connected to a network.

  The external storage medium interface 417 is a medium interface that is detachable from the MFP according to the present embodiment and conforms to the standard of the external storage medium. For example, an SD card, a compact flash (registered trademark), a ROM-DIMM, or the like is used as an external storage medium.

  A system memory 402 is a system memory used as a memory for storing programs and data, a memory for developing programs and data, a drawing memory for printers, and the like, and includes a ROM (Read Only Memory) and a RAM (Random Access Memory) not shown. Consists of. The ROM is a read-only memory used as a program and data storage memory, and the RAM is a writable and readable memory used as a program and data development memory, a printer drawing memory, and the like.

  The ASIC 405 is an IC (Integrated Circuit) for image processing having hardware elements for image processing, and includes an AGP 418, a PCI bus 423, an HDD 407, a local memory 406, a Flash ROM (Read Only Memory) 408, an NVRAM (Non-Non- Volatile Random Access Memory (409), SDRAM (Synchronous Dynamic RAM) 410, and secure device 411 are connected as bridges.

  The ASIC 405 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 405, a memory controller that controls the local memory 406, and a plurality of DMACs (Direct Memory) that rotate image data using hardware logic. Access Controller), FCU (Fax Control Unit) 421, and a PCI unit that performs data transfer via the PCI bus 423 to and from the engine unit 422.

  The local memory 406 is a local memory used as a copy image buffer and a code buffer, and the HDD 407 is a storage for storing image data, programs, font data, and forms. The Flash ROM 408 is a memory in which an external program and data can be written. The NVRAM 409 and the SDRAM 410 are nonvolatile memories that can hold information even when the power is turned off. The secure device 411 issues a warning sound to the user of the MFP 104 according to the present embodiment.

  The FCU 421 is connected to the PCI bus 423 and is used as a memory for temporarily storing facsimile data received when the power is turned off.

  The engine unit 422 is a printer engine that can be connected to the PCI bus 423, and is, for example, a monochrome plotter, a 1-drum color plotter, a 4-drum color plotter, a scanner, or a fax unit. The engine unit 422 includes an image processing part such as error diffusion and gamma conversion in addition to a so-called engine part such as a plotter.

  The operation panel 420 is an operation unit that accepts an input operation from the operator and performs display for the operator.

  Next, among the functions that the various programs installed in the system memory 402 cause the CPU 401 to execute, characteristic functions provided in the MFP 104 according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 5, the MFP 104 according to the present embodiment implements a network control unit 501 by following a name resolution program. The network control unit 501 includes a network communication unit 502, a name resolution response unit 503, a proxy response unit 504, a name resolution request unit 505, and a proxy response execution determination unit 506.

  The network communication unit 502 uses the above-described various network interfaces 412 to 416 to receive a name resolution request or a name resolution response from the client (or DNS server) and a name resolution request to the client (or DNS server) or Mediates the name resolution response sending process.

  The name resolution response unit 503 is a module that receives a name resolution request and transmits a name resolution response. Specifically, the name resolution response unit 503 receives the name resolution request transmitted according to the inquiry protocol (first protocol according to the present invention) (request receiving means according to the present invention). In the present embodiment, a name resolution request transmitted from a client is received via a network communication unit 502 according to a multicast (or broadcast) protocol such as LLMNR, mDNS, or NBT.

  Also, the name resolution response unit 503 determines whether the host name included in the received name resolution request matches the host name of the MFP 104 (name resolution determination unit according to the present invention). When the host name included in the name resolution request matches the host name of the MFP 104, the name resolution response unit 503 transmits the IP address set in the MFP 104 to the client via the network communication unit 502. To do.

  The name resolution request unit 505 is a module that transmits a name resolution request and receives a name resolution response. Specifically, if the host name included in the name resolution request received by the name resolution response unit 503 and the host name of the MFP 104 do not match, the name resolution request unit 505 determines a protocol other than the inquiry protocol (this The name resolution request is transmitted to the information processing terminal according to the second protocol according to the invention (request transmitting means according to the present invention). In the present embodiment, a name resolution request is transmitted to the DNS server 102 via the network communication unit 502 in accordance with a DNS protocol registered in advance. In this embodiment, the name resolution request is transmitted to the DNS server 102. However, the present invention is not limited to this. For example, when there is an information processing terminal (for example, PC1 (106)) capable of resolving a name in the same network, or when the MFP 104 itself functions as a DNS server, As long as the protocol can send a name resolution request to the MFP 104 itself, the name resolution request may be sent using a protocol such as LLMNR, mDNS, or NBT. Alternatively, the name resolution request may be transmitted using the hosts file of the MFP 104 and DNS cache information.

  Further, the name resolution request unit 505 receives a name resolution response including an IP address for the name resolution request transmitted according to a protocol different from the inquiry protocol from the information processing terminal (response receiving means according to the present invention). In the present embodiment, when an IP address corresponding to the host name included in the name resolution request is registered in the DNS server 102, a name resolution response including the IP address is sent to the DNS server 102 via the network communication unit 502. Receive from. When an information processing terminal capable of name resolution exists in the same network, a name resolution response is received from the information processing terminal using a protocol such as LLMNR, mDNS, or NBT.

  The proxy response unit 504 transmits the IP address included in the name resolution response received by the name resolution request unit 505 to the client (response receiving unit according to the present invention). In the present embodiment, the IP address included in the name resolution response is transmitted to the client via the network communication unit 502. In the present embodiment, it is further possible to determine whether or not a proxy response is necessary, and to transmit the IP address included in the name resolution response to the client according to the determination result. Specifically, the proxy response unit 504 determines whether to transmit an IP address included in the name resolution response received by the name resolution request unit 505 (execution of response execution according to the present invention). Determination means). The proxy response unit 504 transmits the IP address according to the determination result by the proxy response execution determination unit 506. A method for determining whether or not a proxy response is necessary will be described below.

  The proxy response execution determination unit 506 is a module that determines whether to transmit the IP address included in the name resolution response received by the name resolution request unit 505. In the present embodiment, the IP address is transmitted using the first determination method for determining whether or not to transmit the IP address depending on the presence or absence of the name resolution response to the name resolution request transmitted to the information processing terminal according to the inquiry protocol. It is determined whether or not. In other words, if a name resolution request is sent using the same protocol as the inquiry protocol and there is no name resolution response, there is no host name response partner included in the name resolution request on the network, so it is determined that a proxy response is required. To do. The waiting time for waiting for the name resolution response may be fixed, for example, 1 second, or may be parameterized and changed according to the network environment. The determination process for determining whether or not to transmit the IP address included in the name resolution response can be shortened by performing the determination process simultaneously with the name resolution process.

  Hereinafter, a procedure of processing for determining whether or not to transmit an IP address by the first determination method will be described in detail.

  First, the name resolution request unit 505 further transmits a name resolution request to the information processing terminal according to the inquiry protocol. In the present embodiment, the name resolution request is sent to the information processing terminal (for example, PC1 (106)) according to the multicast (or broadcast) protocol received by the name resolution response unit 503 via the network communication unit 502. Send.

  Furthermore, the name resolution request unit 505 further receives a name resolution response to the name resolution request transmitted according to the inquiry protocol from the information processing terminal. In the present embodiment, a name resolution response including an IP address transmitted from the information processing terminal is received via the network communication unit 502 according to a multicast (or broadcast) protocol such as LLMNR, mDNS, or NBT.

  When the proxy response execution determination unit 506 does not receive a name resolution response to the name resolution request transmitted by the name resolution request unit 505 according to the inquiry protocol, the IP included in the name resolution response received by the proxy response unit 504 Determine to send an address.

  Next, the procedure of name resolution processing by each module shown in FIG. 5 will be described in detail with reference to FIG.

  First, the client (for example, the file server 103) transmits a name resolution request including the host name “hogehoge” according to LLMNR (step S601). The name resolution response unit 503 transmits according to LLMNR via the network communication unit 502. The received name resolution request is received (step S602).

  Next, the name resolution response unit 503 determines whether or not the host name “hogehoge” included in the received name resolution request matches the host name of the MFP 104 (step S603). When the host name “hogehoge” included in the name resolution request and the host name of the MFP 104 do not match, the name resolution response unit 503 displays the host name “hogehoge” included in the name resolution request and the inquiry protocol ( The LLMNR) information is notified to the proxy response unit 504, and a name resolution process using a protocol different from the inquiry protocol (LLMNR) is requested (step S604).

  When a name resolution process is requested from the name resolution response unit 503, the proxy response unit 504 requests the name resolution request unit 505 for a name resolution process based on the DNS protocol (step S605). The name resolution request unit 505 transmits a name resolution request including the host name “hogehoge” to the DNS server 102 by the DNS protocol via the network communication unit 502 (step S606).

  When the DNS server 102 receives a name resolution request including the host name “hogehoge” from the MFP 104 (step S607), the DNS server 102 searches for an IP address corresponding to the host name “hogehoge” included in the name resolution request. Then, when the IP address “192.168.1.2” corresponding to the host name “hogehoge” is searched, the DNS server 102 transmits the IP address “192.168.1.2” to the MFP 104 (step S608).

  The name resolution request unit 505 receives the name resolution response transmitted from the DNS server 102 via the network communication unit 502 (step S609), and substitutes the IP address “192.168.1.2” included in the name resolution response as a proxy response. Notification is made to the unit 504 (step S610).

  Further, the proxy response unit 504 notifies the proxy response execution determination unit 506 of the host name “hogehoge” and the inquiry protocol (LLMNR) information included in the name resolution request notified from the name resolution response unit 503. A request is made to determine whether a proxy response is necessary (step S611).

  When the proxy response execution determination unit 506 is requested by the proxy response unit 504 to determine whether a proxy response is required, the host name “hogehoge” included in the name resolution request is sent to the name resolution request unit 505. And request a name resolution process by LLMNR (step S612). The name resolution request unit 505 transmits a name resolution request including the host name “hogehoge” to the name resolution apparatus (for example, PC1 (106)) on the network via the network communication unit 502 according to LLMNR (step S613). The name resolution device that has received the name resolution request according to LLMNR determines whether or not the host name of its own device matches the host name “hogehoge” included in the name resolution request (step S614).

  When there is no response to the name resolution request from the name resolution device (step S615), the name resolution request unit 505 notifies the proxy response execution availability determination unit 506 that there is no response to the name resolution request ( Step S616). When it is notified from the name resolution request unit 505 that there is no response to the name resolution request, the proxy response execution determination unit 506 notifies the proxy response unit 504 that a proxy response is necessary (step S617).

  When the proxy response unit 504 is notified by the proxy response execution determination unit 506 that a proxy response is necessary, the proxy response unit 504 sends the IP address “192.168.1.2” notified from the name resolution request unit 505 to the network communication unit 502. To the client (step S618). The client receives the IP address “192.168.1.2” transmitted from the MFP 104 (step S619).

  As described above, according to the MFP 104 according to the present embodiment, the name resolution request transmitted by multicast or broadcast is received, and the host name included in the received name resolution request matches the host name of the terminal itself. If the host name included in the name resolution request does not match the host name of the terminal itself, the name resolution request is sent to the information processing terminal by means other than the means that received the name resolution request. The name resolution response including the IP address for the name resolution request is received from the information processing terminal, and the IP address included in the received name resolution response is transmitted to the request source of the name resolution request. Even if the DNS server address is not set in its own terminal or the name cannot be resolved by the DNS server. Resolution can be able to increase the probability.

(Second Embodiment)
A second embodiment will be described with reference to the accompanying drawings. Since the functions and configuration of the MFP according to the present embodiment are almost the same as those of the first embodiment, only the parts different from the first embodiment will be described. When the MFP according to the present embodiment receives the name resolution request again according to the inquiry protocol, the MFP determines that a proxy response is necessary because there is no host name response partner included in the name resolution request on the network. Thus, since it is not necessary for the MFP to transmit a name resolution request by another means, it is possible to determine whether or not a proxy response is necessary without imposing a load on the MFP.

  The proxy response execution determination unit 506 determines that the IP address needs to be transmitted when the name resolution response unit 503 determines again that the name resolution request has been received according to the inquiry protocol. In this embodiment, whether or not a proxy response is necessary is determined by the second determination method for determining whether or not it is necessary to transmit an IP address depending on whether or not the name resolution request is received again according to the inquiry protocol. To do.

  Hereinafter, a procedure of processing for determining whether or not to transmit an IP address by the second determination method will be described in detail.

  The name resolution response unit 503 further determines whether or not a name resolution request has been received again according to the inquiry protocol. In the present embodiment, the name resolution response unit 503 receives the name resolution request for the first time, the request source of the name resolution request, the host name included in the name resolution request, and the name resolution request again. When the received inquiry protocol, the request source of the name resolution request, and the host name included in the name resolution request match, it is determined that the retry is from the same client. Note that the request source of the name resolution request is specified by the IP address or physical address of the client that transmitted the name resolution request.

  The proxy response execution determination unit 506 determines that a proxy response is necessary when the name resolution response unit 503 determines that there is a retry from the same client.

  Next, the procedure of name resolution processing by each module according to the present embodiment will be described in detail with reference to FIG. FIG. 7 is a sequence diagram showing the procedure of name resolution processing by the MFP. Note that the procedure of name resolution processing by each module according to the present embodiment is almost the same as the flowchart shown in FIG. For steps S701 to S711, refer to the description of FIG.

  When the proxy response execution determination unit 506 is requested by the proxy response unit 504 to determine whether a proxy response is necessary, the proxy response execution unit 506 monitors the name resolution request reception processing by the name resolution response unit 503 (step S712).

  When the client (for example, the file server 103) transmits a name resolution request including the host name “hogehoge” again according to LLMNR (step S713), the name resolution response unit 503 passes through the network communication unit 502. The name resolution request transmitted according to LLMNR is received (step S714). Next, when the received name resolution request is a retry, the name resolution response unit 503 notifies the proxy response execution determination unit 506 that a retry has occurred (step S715).

  Upon receiving the retry notification from the name resolution response unit 503, the proxy response execution determination unit 506 notifies the proxy response unit 504 that a proxy response is necessary (step S716). When the proxy response unit 504 is notified by the proxy response execution determination unit 506 that a proxy response is necessary, the proxy response unit 504 sends the IP address “192.168.1.2” notified from the name resolution request unit 505 to the network communication unit 502. To the client (step S717). The client receives the IP address “192.168.1.2” transmitted from the MFP 104 (step S718).

  On the other hand, when a retry is not performed from the client (step S719), the name resolution response unit 503 notifies the proxy response execution determination unit 506 that there is no retry (step S720). When the proxy response execution determination unit 506 is notified from the name resolution response unit 503 that there is no retry, the proxy response execution determination unit 506 notifies the proxy response unit 504 that there is no need for a proxy response (step S721), and IP address transmission processing The name resolution process ends without performing the process.

  As described above, according to the MFP 104 according to the present embodiment, when there is a retry, there is no response partner of the host name included in the name resolution request on the network. Since it is not necessary for the MFP to send a name resolution request by another means, it is possible to determine whether a proxy response is necessary without imposing a load on the MFP.

(Third embodiment)
A third embodiment will be described. Since the functions and configuration of the MFP according to the present embodiment are almost the same as those of the first and second embodiments, only the parts different from the first and second embodiments will be described. If the domain name included in the name resolution request and the domain name of the MFP do not match, the MFP according to the present embodiment needs to make a proxy response by determining that an IP address needs to be transmitted. Since it can be immediately determined whether or not there is, there is no need for the MFP to send a name resolution request or wait for a retry from the client.

  The proxy response execution determination unit 506 determines that the IP address is to be transmitted when the name resolution response unit 503 determines that the domain name included in the name resolution request and the domain name of the MFP 104 do not match. In the present embodiment, a proxy response is required by the third determination method for determining whether to transmit an IP address depending on whether the domain name included in the name resolution request matches the domain name of the terminal itself. It is determined whether or not. That is, when the domain name included in the name resolution request matches the domain name of the MFP 104, an information processing terminal that inquires about the IP address exists in the same network. Therefore, even if the name resolution request transmission processing by the MFP 104 is not performed, the client can acquire the IP address directly from the information processing terminal that inquired the IP address by using the host name. For this reason, in the present embodiment, if the domain name included in the name resolution request matches the domain name of the MFP 104, it is determined that a proxy response is not necessary.

  Hereinafter, a procedure of processing for determining whether or not to transmit an IP address by the third determination method will be described in detail.

  The name resolution response unit 503 receives a name resolution request including the domain name of the information processing terminal that queries the IP address. In this embodiment, a name resolution request including the FQDN of the information processing terminal that inquires about the IP address is received. Further, the name resolution response unit 503 further determines whether or not the domain name included in the name resolution request matches the domain name of the MFP 104. In the present embodiment, a domain name is extracted from the FQDN included in the received name resolution request, and it is determined whether or not the extracted domain name matches the domain name of the MFP 104.

  If the domain name extracted from the FQDN included in the name resolution request does not match the domain name of the MFP 104, the proxy response execution determination unit 506 needs to make a proxy response to the proxy response unit 504. Is determined.

  As described above, according to the MFP 104 according to the present embodiment, when the domain name included in the name resolution request and the domain name of the MFP do not match, it is determined that the IP address needs to be transmitted. Since it is possible to immediately determine whether it is necessary to make a proxy response, the MFP does not need to send a name resolution request or wait for a retry from the client.

(Fourth embodiment)
A fourth embodiment will be described. Since the functions and configuration of the MFP according to the present embodiment are substantially the same as those of the first to third embodiments, only the parts different from the first to third embodiments will be described. In the MFP according to the present embodiment, the information processing terminal that makes an inquiry about the IP address from the IP address included in the name resolution response, the IP address and subnet mask of the own terminal, and the own terminal are in the same network. If it is determined that there is an IP address, it is determined that there is no need to transmit the IP address, and it is determined whether the information processing terminal that queries the IP address exists in the same segment and can respond to the IP address. It is possible to determine whether it is necessary to make a proxy response.

The proxy response execution determination unit 506 performs information processing for inquiring the IP address of the name resolution request from the IP address included in the name resolution response received from the DNS server by the name resolution request unit 505 and the IP address and subnet mask of the MFP 104. If it is determined that the terminal and the MFP 104 are in the same network, it is determined that it is not necessary to transmit an IP address. In the present embodiment, whether or not the information processing terminal whose name resolution request inquires about the IP address from the IP address included in the name resolution response, the IP address and subnet mask of the own terminal, and the own terminal are in the same network. Therefore, it is determined whether or not a proxy response is necessary by the fourth determination method for determining whether or not it is necessary to transmit an IP address.

Specifically, when it is determined that the network of the information processing terminal that inquires the IP address is different from the network of the MFP 104 by the following formula, it is determined that a proxy response is necessary.
Network of information processing terminal for querying IP address = (IP address received from DNS server) AND (subnet mask of MFP 104)
Network of MFP 104 = (IP address of MFP 104) AND (Subnet mask of MFP 104)

  That is, when the information processing terminal that inquires the IP address and the MFP 104 exist in the same segment, the information processing terminal that inquires the IP address exists in the same network. Therefore, even if the name resolution request transmission processing by the MFP 104 is not performed, the client can acquire the IP address directly from the information processing terminal that inquired the IP address by using the host name. For this reason, in this embodiment, when the network of the information processing terminal that inquires the IP address matches the network of the MFP 104, it is determined that a proxy response is not necessary.

As described above, according to the MFP 104 according to the present embodiment, the information processing terminal and its own terminal whose name resolution request inquires about the IP address from the IP address included in the name resolution response and the IP address and subnet mask of the own terminal. Is determined to exist in the same network, it is determined that there is no need to send an IP address, so that an information processing terminal that queries the IP address exists in the same network (segment) and can respond to the IP address It is possible to determine whether or not it is necessary to make a proxy response after reliably determining whether or not.

(Fifth embodiment)
A fifth embodiment will be described with reference to the accompanying drawings. Since the functions and configuration of the MFP according to the present embodiment are almost the same as those of the first to fourth embodiments, only the parts different from the first and second embodiments will be described. The MFP according to the present embodiment determines whether the IP address needs to be transmitted by the first determination method or the second determination method when the name resolution request includes the domain name of the information processing terminal that queries the IP address. and, if they do not contain the domain name of the information processing terminal name resolution request inquiring an IP address by determining whether more needs to send an IP address to the third determination how the determination process is fixed The response time of the proxy response can be improved as compared with the case where

When the name resolution request includes the domain name of the information processing terminal that queries the IP address, the proxy response execution determination unit 506 determines whether the IP address needs to be transmitted by the first determination method or the second determination method. and, if they do not contain the domain name of the information processing terminal name resolution request inquiring an IP address, it determines whether it is necessary to send more IP addresses in the third determination how. In the present embodiment, the determination method is selected depending on whether or not the host name included in the name resolution request received by the name resolution response unit 503 is described in FQDN.

  FIG. 8 is a flowchart showing a procedure of name resolution processing by the MFP. Steps S801 to S804 and steps S809 to S810 refer to the description of FIG.

The proxy response execution determination unit 506 checks whether or not the host name included in the name resolution request received by the name resolution response unit 503 is described in FQDN (steps S805 and S806). If the host name included in the name resolution request is not described in FQDN (step S806: No), the proxy response execution determination unit 506 determines whether a proxy response is required by the first determination method or the second determination method. Is determined (step S807). On the other hand, if the host name included in the name resolution request is written in FQDN (Step S806: Yes), the proxy response executability determination unit 506 determines whether more proxy response is required in the third determination how (Step S808).

  As described above, according to the MFP 104 according to the present embodiment, the determination method can be selected depending on whether or not the name resolution request includes the domain name of the information processing terminal that queries the IP address. The response time of the proxy response can be improved as compared with the case where

It is a block diagram which shows the structure of the name resolution system concerning 1st Embodiment. It is a sequence diagram which shows the procedure of the name resolution process in the name resolution system concerning 1st Embodiment. It is a flowchart which shows the procedure of the name resolution process by a proxy resolver. 2 is a block diagram illustrating a hardware configuration of an MFP. FIG. 2 is a block diagram illustrating a functional configuration of the MFP. FIG. FIG. 10 is a sequence diagram illustrating a procedure of name resolution processing by the MFP. FIG. 10 is a sequence diagram illustrating a procedure of name resolution processing by the MFP. 6 is a flowchart illustrating a procedure of name resolution processing by the MFP.

Explanation of symbols

101 PC2
102 DNS server 103 File server 104 MFP
105 Router 106 PC1
400 controller 401 CPU
402 System memory 403 NB
404 SB
405 ASIC
406 Local memory 407 HDD
408 Flash ROM
409 NVRAM
410 SDRAM
411 Secure device 412 Ethernet I / F
413 USB I / F
414 IEEE1394 I / F
415 Centronics I / F
416 Wireless I / F
417 I / F for external storage media
418 AGP
419, 423 PCI bus 420 Operation panel 421 FCU
422 Engine unit 501 Network control unit 502 Network communication unit 503 Name resolution response unit 504 Proxy response unit 505 Name resolution request unit 506 Proxy response execution determination unit

Claims (7)

Request receiving means for receiving a name resolution request specifying a host name associated with an IP address assigned to an information processing terminal on another network transmitted according to the first protocol;
Name resolution determination means for determining whether or not the host name included in the received name resolution request matches the host name of the own terminal;
Request transmission for transmitting the name resolution request to the information processing terminal according to a second protocol different from the first protocol when the host name included in the name resolution request does not match the host name of the own terminal Means,
Response receiving means for receiving, from the information processing terminal, a name resolution response including an IP address for the name resolution request transmitted according to the second protocol;
Response sending means for sending the IP address included in the received name resolution response to the request source of the name resolution request;
An information processing terminal comprising: The response transmission means includes
Response execution determination means for determining whether to transmit an IP address included in the name resolution response received by the response reception means;
The information processing terminal according to claim 1, wherein the response transmission unit transmits an IP address according to a determination result by the response execution determination unit.   The response execution determination means is configured to determine whether to transmit an IP address based on the presence or absence of the name resolution response to the name resolution request transmitted to the information processing terminal according to the first protocol. The information processing terminal according to claim 2, wherein whether or not to transmit is determined.   Whether the response execution determination means transmits the IP address by the second determination method for determining whether to transmit the IP address according to whether the name resolution request is received again according to the first protocol. The information processing terminal according to claim 2, wherein the information processing terminal is determined.   The response execution determination means uses a third determination method for determining whether or not an IP address needs to be transmitted based on whether or not the domain name included in the name resolution request matches the domain name of the terminal itself. 3. The information processing terminal according to claim 2, wherein it is determined whether or not to transmit an IP address. The response execution determination unit is configured such that the information processing terminal and the own terminal in which the name resolution request inquires about the IP address from the IP address included in the name resolution response and the IP address and subnet mask of the own terminal are in the same network 3. The information processing according to claim 2, wherein whether or not to transmit an IP address is determined by a fourth determination method for determining whether or not an IP address needs to be transmitted depending on whether or not there is an IP address. Terminal. The response execution determination means includes
When the name resolution request includes a domain name of an information processing terminal that queries an IP address, the first determination method or the second determination method determines whether to transmit an IP address,
If the name resolution request does not contain the domain name of the information processing terminal to query the IP address, claims, characterized in that to determine whether the more third determination how it is necessary to send the IP address The information processing terminal according to any one of 3 to 6.

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