JP2003163701A - Repeater equipment, distribution method for equipment identification information, program, and network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a repeater equipment in which a user can easily refer to setting information. <P>SOLUTION: The repeater equipment for repeating a communication is provided with a receiving part for receiving a packet from a communication terminal, a judgement part for judging whether or not the packet is addressed to a DNS server, a comparing part for comparing a domain name of a URL stored in the packet addressed to the DNS server with a predetermined domain name, and a transmitting part for transmitting the equipment identification information of the relevant repeater equipment to the communication terminal when the domain name of the URL stored in the packet is the same as the predetermined domain name. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a relay device, a device identification information distribution method, a program, and a network system. In particular, the present invention relates to a relay device that allows a user to easily browse setting information.

[0002]

2. Description of the Related Art Recent routers provide setting information of the router in response to a request from a browser of a personal computer that communicates within a LAN, and display it on the browser so that the user can browse it. In order to browse such router setting information, the user requests the router for the setting information by inputting the IP address of the router in the browser.

[0003]

However, in the mode in which the user requests the router for the setting information by inputting the IP address of the router in the browser, the user must remember the IP address of the router. , The setting information of the router cannot be browsed and the setting information cannot be changed. Since the IP address is a list of numbers, it is difficult to remember.

Therefore, an object of the present invention is to provide a relay device, a device identification information distribution method, a program, and a network system that can solve the above problems. This object is achieved by a combination of features described in independent claims of the invention. The dependent claims define further advantageous specific examples of the present invention.

[0005]

That is, according to the first aspect of the present invention, a relay device for relaying communication has a receiving unit for receiving a packet from a communication terminal and a packet for identifying a domain name as device identification information. To determine whether or not the packet is destined for the DNS server, a comparison unit for comparing the domain name of the URL stored in the packet destined for the DNS server with a predetermined domain name, and a packet stored in the packet. URL
And a predetermined domain name are the same, the transmission unit that transmits the device identification information of the relay device to the communication terminal.

The transmitter may transmit an IP address as the device identification information of the relay device. The transmitter may further include a register that holds the IP address of the relay device, and the transmission unit may read the IP address of the relay device from the register and transmit the IP address to the communication terminal.

The determining unit may determine whether or not the packet is addressed to the DNS server based on the destination IP address of the packet received by the receiving unit. The determination unit may determine whether the packet is addressed to the DNS server based on the destination port number of the packet received by the reception unit.

When the domain name of the URL stored in the packet is the same as the predetermined domain name,
A communication control unit that restricts transmission of a packet addressed to the DNS server to the DNS server may be further provided.

Corresponding to a predetermined domain name,
When a storage unit that stores device identification information and a file name of a communication terminal and a communication terminal that is identified by the device identification information that the storage unit stores requests a browsing of a file that the relay device has, the storage unit stores It may further include a communication control unit that permits transmission to the communication terminal of the file indicated by the file name stored in association with the device identification information of the communication terminal.

The storage unit stores the device identification information of the communication terminal in association with the domain name when the domain name of the URL stored in the packet is the same as the predetermined domain name. Good.

According to a second aspect of the present invention, a method of delivering device identification information in a relay device for relaying communication includes a receiving step of receiving a packet from a communication terminal, and the packet using the domain name as the device identification information. A determination step of determining whether or not it is addressed to the DNS server to be converted, a comparison step of comparing the domain name of the URL stored in the packet addressed to the DNS server with a predetermined domain name, and a storage step of the packet And a step of transmitting the device identification information of the relay device to the communication terminal when the domain name of the URL and the predetermined domain name are the same.

According to the third aspect of the present invention, a program for a relay device that relays communication includes a receiving module that causes the relay device to receive a packet from a communication terminal, and the packet uses a domain name as device identification information. A determination module for determining whether or not the DNS server is to be converted,
A comparison module for comparing the domain name of the URL stored in the packet addressed to the S server with a predetermined domain name; a domain name of the URL stored in the packet;
And a transmission module for transmitting the device identification information of the relay device to the communication terminal when the predetermined domain name is the same.

According to a fourth aspect of the present invention, a communication terminal,
A network system that includes a DNS server and a relay device that relays communication between a communication terminal and a DNS server,
The relay device includes a receiving unit that receives a packet from a communication terminal, a determination unit that determines whether the packet is addressed to a DNS server that converts a domain name into device identification information, and a DN.
The comparison unit that compares the domain name of the URL stored in the packet addressed to the S server with the predetermined domain name, the domain name of the URL stored in the packet, and the predetermined domain name are the same. In this case, it has a transmitter for transmitting the device identification information of the relay device to the communication terminal.

It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described through embodiments of the invention, but the embodiments do not limit the claimed invention, and all combinations of the features described in the embodiments Is not always essential to the solution of the invention.

FIG. 1 shows an example of the configuration of a network system according to an embodiment of the present invention. The network system according to the present embodiment includes a relay device 10, communication terminals (PC) 20, 21, and 22, and a DNS (Domain).
A Name System server 30 and a Web server 50 are provided. The relay device 10 includes a DNS server 30 and a Web server via a communication network 40 such as the Internet.
Communicate with the server 50. For example, the relay device 10 is a PC
LAN (Local A) having 20, 21, and 22
This is a router that relays communication between the real network) and a communication network 40 such as the Internet network. Moreover, the relay device 10 may be a bridge, a switching hub, or a gateway that relays communication in a computer network.

The PCs 20, 21 and 22 are provided with DHCP.
(Dynamic Host Configurati
on Protocol) or manually set by the user, I of the relay device 10 as the default gateway is set.
The P address and the IP address of the DNS server are set. Then, the PCs 20, 21, and 22 hold the IP address of the relay device 10 and the IP address of the DNS server 30. Further, in the relay device 10, a URL including the domain name indicating the relay device 10 is set by the user's manual setting. Then, the relay device 10 holds the URL including the domain name indicating the relay device 10.

The user uses the browser of PC 20 to UR
L (Uniform Resource Locato
By specifying rs), the browsing of the home page of the Web server 50 is requested. And PC20 is We
b In order to acquire the IP address of the server 50, a packet addressed to the DNS server 30 is transmitted to the relay device 10 which is the default gateway. In this case, the relay device 10 determines that the received packet is addressed to the DNS server 30, and further determines that the domain name of the URL designated by the user is not the domain name of the relay device 10 and transmits it to the DNS server 30. To do.

The DNS server 30 is a Web server 50 corresponding to the domain name of the URL designated by the user.
The IP address of is searched and acquired. Then, the DNS server 30 transmits the acquired IP address of the Web server 50 to the PC 20 via the relay device 10. And
The PC 20 connects to the Web server 50 via the relay device 10 using the IP address of the Web server 50 acquired from the DNS server 30, acquires the home page corresponding to the URL designated by the user, and displays it on the browser.

Also, the user is required to enter the U including the domain name preset in the relay device 10 in the browser of the PC 20.
By designating the RL, the browsing of the setting information of the relay device 10 is requested. Then, the PC 20 transmits a packet addressed to the DNS server 30 to the relay device 10, which is the default gateway, in order to obtain the IP address of the server corresponding to the domain name of the URL designated by the user. In this case, the relay device 10 determines that the received packet is D
The IP address of the relay device 10 is transmitted to the PC 20 by determining that it is addressed to the NS server 30 and further that the domain name of the URL designated by the user is the domain name of the relay device 10. Then, the PC 20 connects to the relay device 10 using the IP address of the relay device 10, acquires the setting information of the relay device 10 corresponding to the URL designated by the user, and displays it on the browser.

According to the relay device 10 of this embodiment, the user determines the domain name of the relay device 10 and determines the relay device 1
Setting information can be browsed by setting 0 and inputting the set domain name in the browser. Therefore, the user uses the relay device 10 with the domain name that is easy to remember.
By setting to, it is possible to save the trouble of managing the IP address of the relay device 10. Further, when the user manages a plurality of LANs having the relay device 10, I
Since the same domain name can be set for multiple relay devices 10 having different P addresses, the domain name is set to 1
Only by remembering one, it is possible to manage the setting information of the plurality of relay devices 10.

FIG. 2 shows an example of the functional configuration of the relay device 10 according to this embodiment. The relay device 10 includes an external transmission / reception unit 100 that transmits and receives packets via the communication network 40.
Internal transmission / reception unit 112 that transmits / receives packets to / from PCs 20, 21, and 22 in the LAN, and communication control unit 10 that controls communication between external transmission / reception unit 100 and internal transmission / reception unit 112.
6, a storage unit 102 that stores a predetermined domain name of the relay device 10, a register 108 that holds the IP address of the relay device 10, a determination unit 110 that determines the destination of the received packet, and a received packet The comparison unit 104 that compares the domain name of the URL stored in the storage unit 102 with the domain name stored in the storage unit 102.

The internal transmission / reception unit 112 is the PC 2 in the LAN.
Receive packets from 0, 21, and 22. And
The communication control unit 106 decodes the header information of the packet received by the internal transmission / reception unit 112 and performs the routing process of the packet. Then, the communication control unit 106 outputs the packet to the external transmission / reception unit 100. Then, the external transmission / reception unit 100 transmits the packet to the communication network 40 side under the control of the communication control unit 106.

Further, the external transmission / reception unit 100 has a communication network 40.
Receives a packet from the side. Then, the communication control unit 106
Deciphers the header information of the packet received by the external transmission / reception unit 100 and performs the routing process of the packet.
Then, the communication control unit 106 outputs the packet to the internal transmission / reception unit 112. Then, the internal transmission / reception unit 112
Is controlled by the PC 20, 2 based on the control of the communication control unit 106.
The packet is transmitted to 1 or 22.

The judging section 110 judges whether the packet received by the internal transmitting / receiving section 112 is addressed to the DNS server 30. For example, the determination unit 110 may include the internal transmission / reception unit 11
2 the destination I stored in the IP header of the received packet
The packet is sent to the DNS server 3 based on the P address.
It is determined whether the address is 0. Specifically, the determination unit 11
0 is the DNS server 3 input by the user's settings, etc.
The IP address of 0 is held in advance, and the packet is addressed to the DNS server 30 by comparing the IP address with the destination IP address stored in the IP header of the packet received by the internal transmission / reception unit 112. Determine if there is.

In another example, the determination unit 110 determines that the packet is DNS-based on the destination port number stored in the TCP header of the packet received by the internal reception unit 112.
It is determined whether or not it is addressed to the server 30. Specifically, when the destination port number stored in the TCP header of the packet received by the internal receiving unit 112 is the port number 53 indicating the DNS server 30, the determining unit 110 determines that the packet is the DNS server 30. Judge that it is addressed to.

The storage unit 102 stores the domain name of the relay device 10 input by the user by setting or the like. Also,
The storage unit 102 stores the relay device 10 in association with the domain name.
Stores the file name of the file owned by. Storage 10
2 may store a plurality of domain names, or may store different file names in association with each of the plurality of domain names. Further, the storage unit 102 stores the device identification information of the PC 20, 21, or 22 that transmitted the packet in which the domain name is stored, in association with the domain name and the file name. The storage unit 102 includes the PCs 20 and 2.
For example, an IP address is stored as the device identification information of 1 or 22.

The comparing unit 104 stores the UR stored in the packet determined by the determining unit 110 as being addressed to the DNS server 30.
The domain name of L is compared with the domain name of the relay device 10 stored in the storage unit 102. When the storage unit 102 stores a plurality of domain names, the comparison unit 104 determines that the determination unit 1
The storage unit 102 compares the domain name of the URL stored in the packet determined to be addressed to the DNS server 30 with each of the plurality of domain names.

When the determination unit 110 determines that the domain name of the URL stored in the packet determined to be addressed to the DNS server 30 and the domain name of the relay device 10 stored in the storage unit 102 are the same, internal transmission / reception is performed. The unit 112 is the PC 20 that has transmitted the packet in which the domain name is stored,
The device identification information of the relay device 10 is transmitted to 21 or 22. Specifically, the internal transmission / reception unit 112 uses the relay device 1
As the device identification information of 0, the IP address of the relay device 10 is read from the register 108 and transmitted.

When the domain name of the URL stored in the packet determined by the determination unit 110 to be destined for the DNS server 30 is the same as the domain name of the relay device 10 stored in the storage unit 102, communication control is performed. The unit 106 restricts the transmission of the packet storing the domain name to the DNS server 30. Specifically, the communication control unit 106 causes the DNS server 30 of the packet in which the domain name is stored.
To send to. In addition, the communication control unit 106 uses the PC 2 identified by the device identification information stored in the storage unit 102.
When there is a request to browse a file included in the relay device 10 from 0, 21, or 22, the storage unit 102 stores the PC 2
PC 20, 21, or 2 of the file indicated by the file name to be stored in association with the device identification information of 0, 21, or 22.
Allow sending to 2. Further, the communication control unit 106 prohibits transmission of files other than the file indicated by the file name stored in the storage unit 102 in association with the device identification information of the PC 20, 21, or 22 to the PC 20, 21, or 22.

FIG. 3 shows an example of the data structure of the browsing restriction file stored in the storage unit 102 according to this embodiment. The browsing restriction file has a domain name field, a device identification information field, and a file name field. The domain name field stores the domain name assigned to the relay device 10. The domain name is defined by the user's preference and is input by the user. The device identification information field stores the device identification information of the PC 20, 21 or 22. Specifically, the device identification information field stores the device identification information of the PC 20, 21, or 22 that transmitted the packet in which the domain name stored in the domain name field is stored. The device identification information of the PC 20, 21 or 22 is, for example, an IP address. The file name field stores the file name of the file that the relay device 10 has. Specifically, the file name field stores the file name of a file that can be browsed on the PC 20, 21, or 22 identified by the device identification information stored in the device identification information field.

The communication control unit 106 refers to the browsing restriction file and sends the file browsing request to the PC 20, 2
The browsing of the file that the relay device 10 has in 1 or 22 is restricted. For example, the user is
In 1 or 22 browsers, domain name goto
When requesting to browse a file that the relay device 10 has by designating AR230E.admin, the file name pas
swd. cgi, setup. cgi, edita
f. cgi, reset. html, info. cgi
And stat. You can browse the file indicated by cgi. When the user requests the browsing of the file held by the relay device 10 by designating the domain name gotoAR230E on the browser of the PC 20, 21, or 22, the file name info. cgi and stat. c
You can browse the file indicated by gi. Specifically, the user who requests the browsing of the file included in the relay device 10 by designating the domain name gotoAR230E.admin is passwd. Browse cgi and relay device 1
It is possible to change the management password of 0, but specify the domain name gotoAR230E and specify the relay device 10
The user who requested to view the file
wd. Since the cgi cannot be browsed, the management password of the relay device 10 cannot be changed.

FIG. 4 shows a flow chart of a method of distributing the device identification information of the relay device 10 according to this embodiment. First, the internal transmission / reception unit 112 uses the PCs 20 and 2 in the LAN.
The packet is received from 1 or 22 (S100). Then, the determination unit 110 determines whether the IP address of the packet received by the internal transmission / reception unit 112 is the IP address of the DNS server 30 (S102). Destination I of the packet received by the internal transmission / reception unit 112 in S102
When determining that the P address is not the IP address of the DNS server 30, the external transmission / reception unit 100 transmits the packet to the communication network 40 side based on the destination IP address of the packet (S104). Then, the flow of the device identification information distribution method according to the present embodiment ends.

The destination IP address of the packet received by the internal transmitting / receiving unit 112 in S102 is the DNS server 30.
If it is determined that the IP address is
Is the domain name of the URL stored in the packet,
The domain name of the relay device 10 stored in the storage unit 102 is compared (S106). If the domain name of the URL stored in the packet does not match the domain name stored in the storage unit 102 in S106, the external transmission / reception unit 1
00 transmits the packet to the communication network 40 side based on the destination IP address of the packet (S104). That is, the external transmission / reception unit 100 transmits the packet to the DNS server 30. Then, the flow of the device identification information distribution method according to the present embodiment ends.

U stored in the packet in S106
When the domain name of the RL matches the domain name stored in the storage unit 102, the communication control unit 106 prohibits transmission of a packet storing the domain name to the DNS server 30 (S108). Then, the storage unit 102
The IP address of the PC 20, 21, or 22 that transmitted the packet is stored in association with the domain name stored in the storage unit 102 (S110). Then, the internal transceiver 1
Reference numeral 12 indicates the IP address of the relay device 10 in the register 108.
PCs 21 and 21 that read packets from the
Alternatively, it is transmitted to 22 (S112). Then, the flow of the device identification information distribution method according to the present embodiment ends.

FIG. 5 shows a flowchart of a method for restricting file browsing of the relay device 10 according to this embodiment. First, the internal transmission / reception unit 112 uses the PCs 20 and 2 in the LAN.
The packet is received from 1 or 22 (S200). Then, the determination unit 110 determines whether the destination IP address of the packet received by the internal transmission / reception unit 112 is the IP address of the relay device 10 (S202). The destination I of the packet received by the internal transmission / reception unit 112 in S202
When it is determined that the P address is not the IP address of the relay device 10, the external transmission / reception unit 100 determines the destination IP of the packet.
The packet is transmitted to the communication network 40 side based on the address (S204). Then, the flow of the device identification information distribution method according to the present embodiment ends.

In step S202, the destination IP address of the packet received by the internal transmission / reception unit 112 is I of the relay device 10.
When it is determined that the address is the P address, the communication control unit 106
Refers to the browsing restriction file stored in the storage unit 102 (S206). Then, the communication control unit 106 uses the PC 2
The file name of the file requested to be browsed by 0, 21, or 22 is the source IP address of the packet received by the internal transmitter / receiver 112, that is, the IP of the PC 20, 21 or 22.
Search whether it is stored in association with the address,
It is determined whether browsing of the file by the PC 20, 21, or 22 is permitted (S208). S20
If it is determined that the file is not permitted to be browsed in 8, the internal transmission / reception unit 112 displays an error message indicating that the file is prohibited to be browsed on the PC.
It is transmitted to 20, 21, or 22 (S210).

When it is determined in S208 that viewing of the file is permitted, the internal transmitting / receiving unit 112
The file is transmitted to the PC 20, 21, or 22 (S212). Then, the flow of the device identification information distribution method according to the present embodiment ends.

FIG. 6 shows an example of the hardware configuration of the PC 20 according to this embodiment. PC20 is CPU700
A ROM 702, a RAM 704, a communication interface 706, a hard disk drive 708, a database interface 710, a floppy (registered trademark) disk drive 712, and a CD-ROM drive 714. The CPU 700 operates based on programs stored in the ROM 702 and the RAM 704, and controls each unit. The communication interface 706 is
It communicates with the relay device 10 via a computer network. The database interface 710 writes data to the database and updates the contents of the database.

Floppy disk drive 712 reads data or programs from floppy disk 720 and provides them to communication interface 706. CD-R
The OM drive 714 reads data or programs from the CD-ROM 722 and provides them to the communication interface 706. The communication interface 706 is a floppy disk drive 712 or a CD-ROM drive 714.
The data or program provided by the relay device 10 is transmitted to the relay device 10. The database interface 710 connects to various databases 724 to send and receive data.

The program provided to the relay device 10 is
It is stored in a recording medium such as a floppy disk 720 or a CD-ROM 722 and provided by the user. The program stored in the recording medium may be compressed or uncompressed. The program is read from the recording medium, and the relay device 10 is accessed via the communication interface 706.
And is executed in the relay device 10.

The program stored in the recording medium and provided, that is, the program installed in the relay device 10, has, as functional configurations, an internal transmission / reception module, an external transmission / reception module, a communication control module, a storage module, and a determination module. And a comparison module. The operation of each module working on the relay device 10 is the same as the operation of the corresponding member in the relay device 10 described in FIGS. 1 to 5, and thus the description thereof is omitted.

The floppy disk 720 or the CD-ROM 722 as an example of the recording medium shown in FIG.
The relay device 10 in all the embodiments described in the present application
It is possible to store some or all of the functions of the above.

These programs may be read directly from the recording medium by the relay device 10 and executed, or may be installed in the relay device 10 and then executed in the relay device 10. Furthermore, the program may be stored in a single recording medium or a plurality of recording media. Further, it may be stored in an encoded form.

As the recording medium, a floppy disk,
In addition to the CD-ROM, an optical recording medium such as a DVD or PD, a magneto-optical recording medium such as an MD, a tape medium, a magnetic recording medium, or a semiconductor memory such as an IC card or a miniature card can be used. Further, a storage device such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet may be used as a recording medium to provide the program to the relay device 10 via the communication network.

According to the relay device 10 of the present embodiment, the user designates the domain name set in the relay device 10 according to the user's preference in the browser of the PC 20, 21 or 22 so that the relay device 10 can be operated. You can browse the setting information of. Therefore, the user does not need to remember the IP address of the relay device 10, and can save the trouble of managing the IP address of the relay device 10.

Further, a plurality of domain names are assigned to the relay device 10, and each domain name is designated to specify the relay device 1
PCs 20 and 21 requesting to browse the files owned by 0,
Or by limiting the files that 22 can view,
The authority to view and change the setting information of the relay device 10 can be controlled for each user. For example, by notifying the network administrator and the general user of different domain names, it is possible to prohibit the general user from viewing and changing the predetermined setting information in the setting information of the relay device 10, and the operation of the general user. It is possible to prevent the setting information of the relay device 10 from being changed due to a mistake or the like.

Although the present invention has been described using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. Various changes or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

[0049]

As is apparent from the above description, according to the present invention, it is possible to provide a relay device that allows the user to easily browse the setting information.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a configuration of a network system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a functional configuration of a relay device 10 according to the present embodiment.

FIG. 3 is a diagram showing an example of a data configuration of a browsing restriction file stored in a storage unit 102 according to the present embodiment.

FIG. 4 is a flowchart of a method of delivering device identification information of the relay device 10 according to the present embodiment.

FIG. 5 is a flowchart of a file browsing restriction method of the relay device 10 according to the present embodiment.

FIG. 6 is a diagram showing an example of a hardware configuration of a PC 20 according to the present embodiment.

[Explanation of symbols]

10 relay equipment 20, 21, 22 PC 30 DNS server 40 communication network 50 Web server 100 External transceiver 102 storage 104 Comparison section 106 communication control unit 108 registers 110 Judgment section 112 Internal transceiver 700 CPU 702 ROM 704 RAM 706 Communication interface 708 hard disk drive 710 database interface 712 floppy disk drive 714 CD-ROM drive 720 floppy disk 722 CD-ROM 724 Various databases

Claims (11)

[Claims] 1. A relay device for relaying communication, comprising: a receiver for receiving a packet from a communication terminal; and determining whether the packet is addressed to a DNS server for converting a domain name into device identification information. And a URL stored in the packet addressed to the DNS server
A comparison unit that compares the domain name of the URL with a predetermined domain name, and if the domain name of the URL stored in the packet and the predetermined domain name are the same, the relay A relay device, comprising: a transmitter that transmits device identification information of a device to the communication terminal. 2. The relay device according to claim 1, wherein the transmission unit transmits an IP address as the device identification information of the relay device. 3. A register for holding the IP address of the relay device is further provided, and the transmission unit reads the IP address of the relay device from the register and transmits the IP address to the communication terminal. The relay device according to item 2. 4. The determination unit determines whether or not the packet is addressed to the DNS server, based on a destination IP address of the packet received by the reception unit. The listed relay equipment. 5. The determining unit determines whether the packet is addressed to the DNS server, based on a destination port number of the packet received by the receiving unit. The listed relay equipment. 6. The transmission of the packet addressed to the DNS server to the DNS server is restricted when the domain name of the URL stored in the packet and the predetermined domain name are the same. The relay device according to claim 1, further comprising a communication control unit that operates. 7. A storage unit for storing device identification information and a file name of the communication terminal in association with the predetermined domain name, and the communication identified by the device identification information stored in the storage unit. When there is a request from the terminal to browse the file of the relay device, the storage unit transmits to the communication terminal the file indicated by the file name stored in association with the device identification information of the communication terminal. The relay device according to claim 1, further comprising: a communication control unit that permits the communication. 8. The storage unit stores device identification information of the communication terminal when the domain name of the URL stored in the packet and a predetermined domain name are the same. The relay device according to claim 7, wherein the relay device is stored in association with a domain name. 9. A method of delivering device identification information in a relay device for relaying communication, comprising a receiving step of receiving a packet from a communication terminal, and the packet addressed to a DNS server for converting a domain name into device identification information. And the URL stored in the packet addressed to the DNS server.
Comparison step of comparing the domain name of the relay device with a predetermined domain name, and when the domain name of the URL stored in the packet and the predetermined domain name are the same, the relay device concerned And a step of transmitting the device identification information to the communication terminal. 10. A program for a relay device that relays communication, comprising: a receiving module that causes the relay device to receive a packet from a communication terminal; and a DNS server that the packet converts a domain name into device identification information. And a URL stored in the packet addressed to the DNS server.
Comparison module for comparing the domain name of the URL with a predetermined domain name, and the relay device when the domain name of the URL stored in the packet and the predetermined domain name are the same. And a transmission module for transmitting the device identification information of 1. to the communication terminal. 11. A network system comprising a communication terminal, a DNS server, and a relay device that relays communication between the communication terminal and the DNS server, wherein the relay device receives a packet from the communication terminal. A determination unit that determines whether the packet is addressed to the DNS server that converts a domain name into device identification information, and a URL stored in the packet addressed to the DNS server.
A comparison unit that compares the domain name of the relay device with a predetermined domain name, and if the domain name of the URL stored in the packet and the predetermined domain name are the same, the relay device is And a transmitter for transmitting the device identification information of 1. to the communication terminal.