JP2011199582A - Network connection apparatus and network connection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To redirect to an IP address with the longest residual time period.SOLUTION: A network card 10 has: a network communication part 12 that communicates with an apparatus connected to a network 60, an addressing processor 14 that generates a plurality of IP addresses based on information included in a packet transmitted by a plurality of routers connected to the network 60 and sets the generated IP addresses in the network 60; an address determination part 22 that determines a second IP address with the longest residual time period among the plurality of IP addresses when receiving a reading command signal transmitted from a client apparatus 50 connected to the network 60 to a first IP address that is one of the plurality of IP addresses; and a redirection requesting part 24 that requests the client apparatus 50 to make redirection to the second IP address when the first IP address is different from the second IP address.

Description

  The present invention relates to a network connection device and a network connection method.

Currently, IP (Internet Protocol) is used as a routing protocol in the widespread Internet. Currently, the commonly used IP is IPv4 (Internet Protocol version 4), and an address (IP address) consisting of 32 bits is used as a source / destination.
In Internet communication, a global IP address that uniquely assigns a 32-bit IP address to each source / destination is adopted, and each source / destination is determined according to the IP address. However, the Internet world is rapidly expanding, and the limited address space of IPv4, that is, the exhaustion of global addresses has become a problem. In order to solve this problem, as a next generation IP address, IPv6 (Internet Protocol version 6) having a new address space by extending the IP address space from 32 bits to 128 bits has been proposed and put into practical use.

  As shown in Patent Document 1 below, when such an IP address expires, the function is interrupted by a router or the like on the network, so the connection process is performed again to obtain the IP address. There was a need.

JP 2009-5189 A

  However, even if it is desired to maintain the connection state for a long time, it is disconnected when the expiration date of the IP address ends, so that the connection process is complicated again and requires time and effort. An object of the present invention is to redirect to an IP address having the longest remaining time.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
The network connection device according to this application example is a network connection device that operates depending on the information processing device by connecting to the information processing device, and connects the information processing device and the network in a communicable manner. A network communication unit that communicates with a device connected to the network, and a plurality of IP addresses generated based on information included in a packet transmitted by a plurality of IP address assignment devices connected to the network, An address setting unit configured to set the IP address to be usable in the network; and a signal transmitted from a client device connected to the network to a first IP address that is one of the plurality of IP addresses. When received by the communication unit, it is included in the packet and is included in the plurality of IP addresses. When the first IP address and the second IP address are different from the address determination unit that determines the second IP address having the longest remaining time indicating the remaining remaining time, the first IP address is different from the second IP address. And a redirect request unit that requests redirection to the second IP address.

  According to such a configuration, the network connection device receives a signal transmitted from the client device to the first IP address that is one of the IP addresses generated for each of the plurality of IP address assignment devices. If the second IP address having the longest remaining time indicating the remaining usable time is determined from among the plurality of IP addresses, and the first IP address and the second IP address are different, Request redirection to the second IP address. Therefore, the frequency of performing the network reconnection process can be reduced by selecting the IP address with the longest remaining time as necessary.

[Application Example 2]
The network connection method according to this application example is a network connection method that operates depending on the information processing device by connecting to the information processing device, and connects the information processing device and the network in a communicable manner. An address setting step of generating a plurality of IP addresses based on information included in a packet transmitted by a plurality of IP address assignment devices connected to the network, and setting the generated plurality of IP addresses to be usable in the network A reception step of receiving a signal transmitted from a client device connected to the network to a first IP address that is one of the plurality of IP addresses, and when the signal is received, the packet is included in the packet The second IP address having the longest remaining time indicating the remaining usable time among the plurality of IP addresses. An address determination step for determining a request, and a redirect request step for requesting the client device to redirect to the second IP address when the first IP address and the second IP address are different. It is characterized by having.

  According to such a method, the network connection apparatus receives a signal transmitted from the client apparatus to the first IP address that is one of the IP addresses generated for each of the plurality of IP address assignment apparatuses. If the second IP address having the longest remaining time indicating the remaining usable time is determined from among the plurality of IP addresses, and the first IP address and the second IP address are different, Request redirection to the second IP address. Therefore, the frequency of performing the network reconnection process can be reduced by selecting the IP address with the longest remaining time as necessary.

1 is a block diagram showing a configuration of a network card according to an embodiment of the present invention. The flowchart which shows the flow of a process of the network card which concerns on embodiment of this invention.

  Hereinafter, the network connection device will be described with reference to the drawings.

(Embodiment)
FIG. 1 is a block diagram illustrating a configuration of a network card 10 that is a network connection device that connects a scanner device 30 that is an information processing device and a network 60 so as to communicate with each other as an embodiment of the present invention.
When the network card 10 is attached to the scanner device 30, the scanner device 30 and the network 60 are communicably connected as nodes in the network 60.
The network 60 is connected to a router A (40) and a router B (45) having a DHCP (Dynamic Host Configuration Protocol) function. The router A (40) and the router B (45) are both connected to the Internet 65. Further, a DNS (Domain Name System) server 55 and a client device 50 are connected to the Internet 65. Therefore, the network card 10 is communicably connected to the DNS server 55 and the client device 50 via the network 60 and the Internet 65.

  The network card 10 includes a network communication unit 12, an addressing processing unit 14, a redirect unit 20, and a device communication unit 16. The redirect unit 20 includes an address determination unit 22 and a redirect request unit 24.

The network card 10 includes, as hardware, a CPU, a ROM, a RAM, a flash memory, a MAC (Media Access Control) controller, and the like, all of which are not shown.
The network communication unit 12 transmits / receives information to / from the client device 50 via the network 60 based on a layered protocol such as an OSI (Open System Interconnection) reference model. The network communication unit 12 is configured to be compatible with IPv6, which is a communication protocol, but is not limited to this.

  The addressing processing unit 14 is an address setting unit, communicates with the router A (40) and the router B (45), and acquires IPv6 addresses (first IP address and second IP address) based on the IPv6 protocol, respectively. To do. Specifically, the addressing processing unit 14 receives router advertisement (RA) packets transmitted by the router A (40) and the router B (45), respectively, and receives the prefix of the received RA packet and its link local An IPv6 address is generated by combining the lower 64 bits of the address. The link local address is automatically generated from the MAC address or the like so as to be unique within the network 60. The generated IPv6 address is referred to by the address determination unit 22 as necessary.

Further, the addressing processing unit 14 requests host names from the router A (40) and the router B (45), the host names sent from the router A (40) and the router B (45), and the generated IPv6. Each address is registered in the DNS server 55. As a result, the client device 50 can perform name resolution and can communicate with the network card 10. A detailed procedure for registering IP address and host name information in the DNS server 55 is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-228736. In the present embodiment, communication with the client device 50 is assumed to be a redirectable transfer protocol such as HTTP (HyperText Transfer Protocol).
The redirect unit 20 starts a service in response to the network communication unit 12 receiving a signal transmitted from the client device 50 to the first IP address, for example, a read command signal. In other words, if there is an IP address that has a remaining time (expiration date) indicating the remaining usable time that is longer than the first IP address among the IP addresses that can be used by the network card 10, redirect to the IP address. Is requested to the client device 50. In the present embodiment, the redirect is requested by instructing the IP address having the longest expiration date. However, the present invention is not limited to this, and a mode in which the redirect is requested by instructing the IP address having the shortest expiration date can be assumed. .

The address determination unit 22 acquires information on the expiration date of the IPv6 address, and the first IP address used by the client device 50 is usable time than other usable addresses (second IP address). Whether or not is long.
In the present embodiment, the address determination unit 22 acquires a parameter related to an expiration date (for example, Router Lifetime) included in the RA packet corresponding to each IPv6 address, and acquires the expiration date of the IPv6 address based on the acquired parameter. To do. Note that the expiration date of the acquired IPv6 address is periodically updated inside the network card 10. In this case, it may be updated in accordance with notifications from the router A (40) and the router B (45). When the address determination unit 22 determines that the second IP address has the longest usable time, the information on the second IP address is sent to the redirect request unit 24. On the other hand, when the first IP address has the longest usable time, the address determination unit 22 does not send information to the redirect request unit 24.
When the information on the second IP address is sent from the address determination unit 22, the redirect request unit 24 requests the client device 50 to redirect the client device 50 with the second IP address. Send.

The device communication unit 16 communicates with the scanner device 30 and also communicates with the network communication unit 12. In the present embodiment, communication via USB (Universal Serial Bus) is assumed, but the present invention is not limited to this.
The scanner device 30 is a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a light source, an optical system, a photoelectric conversion element, a scanning drive system, and a document paper automatic supply, all of which are not shown. A paper device (ADF) and a liquid crystal panel are provided as hardware. In this embodiment, the scanner device 30 is assumed to be a single-function device, but is not limited to this, and may be in the form of a multifunction machine having a printer or a copy function.
FIG. 2 is a flowchart showing a processing flow of the network card 10. After activation, the network card 10 assigns respective IPv6 addresses based on RA messages sent from the router A (40) and the router B (45) (step S100) <address setting process>.

Next, the network card 10 registers the host name and the IPv6 address in the DNS server 55 (step S102). Subsequently, the network card 10 activates a redirect service by the redirect unit 20 (step S105).
Next, the network card 10 determines whether or not a read command signal has been received from the client device 50 (step S110) <receiving step>. The read command signal is transmitted by the client device 50 using the acquired first address after acquiring the first address.
Here, when the network card 10 cannot receive the read command signal from the client device 50 (No in step S110), the process proceeds to step S140.

On the other hand, when the network card 10 has received the read command signal from the client device 50 (Yes in Step S110), the network card 10 acquires the first address used for communication with the external device (Step S110). S115).
Subsequently, the network card 10 acquires a second address that can be used for the longest time for communication with the external device (step S120).
Next, the network card 10 determines whether or not the first address matches the second address (step S125) <address determination step>. If the first address matches the second address (Yes in step S125), the currently used address has the longest usable time, and the process proceeds to step S140.

On the other hand, if the first address and the second address do not match (No in step S125), it is determined whether or not the second address can be used (step S130).
If the second address can be used (Yes in step S130), the network card 10 requests the client device 50 to redirect the second address (step S135) <redirect request process>, and proceeds to step S140. . The client device 50 that has received the redirect request transmits a read command signal again after connecting with the designated second address.

On the other hand, if the second address cannot be used (No in step S130), the process proceeds to step S140.
In step S140, the network card 10 determines whether or not to end the process (step S140). If not (No in step S140), the network card 10 returns to step S110. On the other hand, if the process is to be terminated (Yes in step S140), the redirect service is terminated (step S145), and the series of processes is terminated.

According to the embodiment described above, the following effects can be obtained.
(1) Since the scanner device 30 and the client device 50 are connected with an address having the longest usable time, the troublesomeness of performing reconnection processing due to disconnection in the middle is reduced, and the scanner device 30 and the client device 50 can be used for a long time. Communication can be maintained.

As mentioned above, although this invention was demonstrated based on embodiment shown in figure, this invention is not limited to this embodiment, The modification as described below can also be assumed.
(1) In this embodiment, a single network card 10 is attached to the scanner device 30, but a plurality of network cards 10 are attached and connected to respective routers via different networks such as wired connection and wireless connection. A mode is also good.
(2) The information processing apparatus is not limited to the scanner apparatus 30 and may be an image output apparatus such as a printer or a projector.
(3) Before requesting redirection by designating an address to the client device 50, it may be confirmed whether or not the designated address can be used for communication with the client device 50.
Moreover, the apparatus which implements the above methods may be realized by a single apparatus or may be realized by combining a plurality of apparatuses, and includes various aspects.

  DESCRIPTION OF SYMBOLS 10 ... Network card, 12 ... Network communication part, 14 ... Addressing process part, 16 ... Device communication part, 20 ... Redirect part, 22 ... Address determination part, 24 ... Redirection request part, 30 ... Scanner apparatus, 40 ... Router A, 45 ... Router B, 50 ... Client device, 55 ... DNS server, 60 ... Network, 65 ... Internet.

Claims (2)

A network connection device that operates depending on the information processing device by connecting to the information processing device, and connects the information processing device and the network so as to communicate with each other.
A network communication unit that communicates with a device connected to the network;
An address setting unit that generates a plurality of IP addresses based on information included in a packet transmitted by a plurality of IP address allocation devices connected to the network, and sets the generated plurality of IP addresses to be usable in the network When,
When the network communication unit receives a signal transmitted from a client device connected to the network to a first IP address that is one of the plurality of IP addresses, the signal is included in the packet, and the plurality of IPs An address determination unit that determines the second IP address having the longest remaining time indicating the remaining time that can be used in the address;
A network connection device comprising: a redirect request unit that requests the client device to redirect to the second IP address when the first IP address is different from the second IP address. . A network connection method that operates depending on the information processing device by connecting to the information processing device, and connects the information processing device and the network in a communicable manner,
An address setting step of generating a plurality of IP addresses based on information included in a packet transmitted by a plurality of IP address assignment devices connected to the network, and setting the generated plurality of IP addresses to be usable in the network When,
A receiving step of receiving a signal transmitted to a first IP address that is one of the plurality of IP addresses from a client device connected to the network;
When receiving the signal, an address determination step of determining a second IP address that is included in the packet and has the longest remaining time indicating the remaining time that can be used among the plurality of IP addresses;
A network connection method comprising: a redirect requesting step for requesting the client device to redirect to the second IP address when the first IP address is different from the second IP address. .

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