KR20060064964A - Method of selecting user-desired dhcp server from multiple dhcp servers - Google Patents

Abstract

A method of selecting a desired DHCP server from a plurality of DHCP servers is disclosed. In the method of selecting a DHCP server according to the present invention, generating a DHCP server list including parameters related to a DHCP server, and comparing a DHCP server related parameter included in the DHCP server list with a DHCP parameter desired by the user may request a DHCP service. Determining a DHCP server, transmitting a message requesting DHCP service to the determined DHCP server, waiting for the determined DHCP server to transmit a message acknowledging the DHCP service for a predetermined time, and from the determined DHCP server within a predetermined time If a message for accepting the DHCP service is received, the step of assigning the network interface included in the DHCP service approval message to the network interface. By selecting a DHCP server that satisfies a desired parameter among a plurality of DHCP servers, even if a plurality of DHCP servers having various parameters exist on the network, one of them can be selected to receive various DHCP services selectively. Can be.

Description

Method of selecting user-desired DHCP server from multiple DHCP servers}

1 is a block diagram showing the configuration of a network printing system.

2 is a flowchart illustrating an embodiment of a method for receiving an IP address from a DHCP server.

3 is a flowchart illustrating an embodiment of a method of selecting a DHCP server according to the present invention.

4 is a diagram illustrating an embodiment of a DHCP server list.

5 is a flowchart illustrating an embodiment of a method for creating a DHCP server list.

Figure 6 is a flow diagram illustrating one embodiment of a method for setting desired DHCP server parameters by showing a user a list of DHCP servers and then selecting one of them.

7 is a flowchart illustrating an embodiment of a method of selecting another DHCP server by changing a DHCP server currently being serviced.

<Description of the code>

10: central processing unit (CPU) 20: data processing unit

30: storage device 40: input and output device processing unit

50: data receiving unit 60: network control unit

70: printing device 80: display device

90: user input device 100: printing client

110: Network 700: DHCP Server List

710: IP address of the DHCP server 711 to 713: DHCP parameters

720: IP address to provide 730: Subnet to provide

740: gateway to provide 750: lease period

The present invention relates to the transmission of digital information, and more particularly, to a method of selecting a server having a parameter desired by a user among a plurality of dynamic host configuration protocol servers.

Dynamic Host Configuration Protocol (DHCP) refers to a communication protocol for automatically allocating and managing configuration information necessary for executing TCP / IP communication. Details of DHCP are specified in RFC 1541.

The DHCP server manages a database of DHCP servers called scopes and assigns IP addresses to DHCP clients. The DHCP server database stores parameters such as IP address, subnet mask, gateway, client MAC address, and lease length.

In the conventional use of DHCP, only one DHCP server exists on a network that can be used by DHCP clients. Therefore, the network configuration on the DHCP client only needs to receive server parameters from the DHCP server and dynamically configure them.

In recent years, however, a plurality of DHCP servers exist in a network, and a DHCP client has to select one among DHCP servers having various server parameters. However, the RFC protocol and the like did not have a clear setting for the selection of one of the plurality of DHCP servers. Therefore, a method of selecting one DHCP server according to a user's preference from a plurality of DHCP servers has been required.

An object of the present invention is to provide a method for selecting one DHCP server desired by a user among a plurality of DHCP servers.

In order to achieve the above technical problem, a DHCP server selection method includes: generating a DHCP server list including parameters related to a dynamic host configuration protocol (DHCP) server on a network; Determining a DHCP server to request a DHCP service by comparing a DHCP server related parameter included in the DHCP server list with a DHCP parameter desired by a user; Transmitting a message requesting a DHCP service to the determined DHCP server; Waiting for a predetermined time for the determined DHCP server to transmit a message for approving a DHCP service; And when receiving a message for approving the DHCP service from the determined DHCP server within the predetermined time, assigning a network address included in the DHCP service approval message to a network interface.

Hereinafter, a method of selecting a DHCP server according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing the configuration of a network printing system as a representative example of setting a network address using DHCP. Referring to FIG. 1, a network printing system includes a printing client 100, a printing device 70, a display device 80, a user input device 90, and a network 110.

The printing client 100 includes a central processing unit (CPU) 10, a data processing unit 20, a storage device 30, an input / output device processing unit 40, a data receiving unit 50, and a network controller 60. do. The central computing unit 10 executes code for operating a network printing system. The data processor 20 processes data on a network printing system. The storage device 30 stores data on a network printing system such as a code for processing printing format data or received printing format data. The input / output device processing unit 40 is in charge of communication with input / output devices such as a printing device 70, a display device 80 such as a monitor, and a user input device 90 such as a keyboard. The data receiver 50 receives data from the network controller 60. The network controller 60 is connected to a wired or wireless network to transmit and receive data from a program of the network printing system to the network 110 or from the network 110 to a program of the network printing system.

2 is a flowchart illustrating an embodiment of a method of receiving an IP address from a general DHCP server.

Referring to FIG. 2, first, a DHCP client transmits a DHCPDISCOVER message to a network by broadcast (S100). The DHCPDISCOVER message is for finding a DHCP server on the network.

Upon receiving the DHCPDISCOVER message, the DHCP server on the network transmits a DHCPOFFER message (S110). The DHCPOFFER message is to provide DHCP service and includes DHCP server parameters such as an assignable IP address.

When the DHCP client receives the DHCPOFFER message, the DHCP client transmits a DHCPREQUEST message (S120). The DHCPREQUEST message is a request for DHCP service.

The DHCP server receiving the DHCPREQUEST message sends a DHCPACK message to the DHCP client (S130). The DHCPACK message is a message for approving the DHCP service. The DHCPACK message includes parameters related to the service to be provided, such as a network address available to the DHCP client.

The DHCP client receiving the DHCPACK message sets the network address included in the DHCPACK message to its network interface (S140).

3 is a flowchart illustrating an embodiment of a method of selecting a DHCP server according to the present invention.

First, the DHCP client generates a list of DHCP servers (S200). The DHCP server list contains various parameters required for dynamic host configuration on the DHCP server. This is illustrated in FIG. 4.

4 is a diagram illustrating an embodiment of a DHCP server list.

Referring to FIG. 4, the DHCP server list 700 includes various parameters of a DHCP server. In the example of FIG. 4, the IP address of the DHCP server (DHCP server IP, 710), the IP address to be provided to the DHCP client (offered IP, 720), the subnet to be provided (offered subnet, 730), the gateway to be provided (offered gateway, 740, length of lease 750, and the like are included in the DHCP server list.

When the DHCP server list is created, it determines the DHCP server to receive the service from the DHCP server included in the list (S210). To determine the DHCP server, compare the DHCP server-related parameters included in the DHCP server list with the desired DHCP parameters, and select one of the DHCP servers included in the list that satisfies the desired DHCP parameter. do.

When the DHCP server to request the service is determined, it transmits a DHCPREQUEST message to the determined DHCP server (S220), and waits until the determined DHCP server transmits a DHCPACK message (S230).

At this time, in order to confirm that the DHCP server can provide a service, a predetermined time is determined and a method of waiting for this time is taken. This is because the determined DHCP server may not be able to service the client, such as after providing a DHCPOFFER message to other DHCP clients.

It is checked whether the DHCPACK message is received within a predetermined time (S240), and if it is received within a predetermined time, the network address included in the DHCPACK message is set to the network interface (S250). If the message is not received within a certain time, the user deletes some items of the desired DHCP parameter (S260), and performs again from the step (S210) of determining a DHCP server to receive the service.

5 is a flowchart illustrating an embodiment of a method for creating a DHCP server list. This describes the step S200 of FIG. 3 in more detail.

First, the DHCP server list is initialized (S310). This deletes the DHCP server list if it is already created.

After the DHCP server list is initialized, the DHCPDISCOVER message is broadcasted to the network (S320).

After transmitting the DHCPDISCOVER message, and waits for a predetermined time to receive a DHCPOFFER message (S330). After waiting for a predetermined time to check whether the DHCPOFFER message has been received (S340), if a DHCPOFFER message is received within a certain time, save the DHCPOFFER message (S350), and in step S330 to receive a DHCPOFFER message from another DHCP server Go back.

If the DHCPOFFER message has not been received within a certain time, it is determined that one or more DHCPOFFER messages have been received since the DHCPOFFER message has been received from all the serviceable DHCP servers on the network (S360). If at least one DHCPOFFER message is received, a list of DHCP servers is generated using the stored DHCPOFFER message (S370). If one or more DHCPOFFER messages have not been received, start again from step S320.

Figure 6 is a flow diagram illustrating one embodiment of a method for setting desired DHCP server parameters by showing a user a list of DHCP servers and then selecting one of them. This is an embodiment of step S210 of FIG.

Display the list of DHCP servers to the user (S410), and receive the input by selecting one of the servers displayed in the list of DHCP servers from the user (S420).

When the user selects one DHCP server, the server stores the DHCP server parameter related to the selected server in a desired DHCP parameter (S430).

Since the currently selected server is a server that satisfies a parameter desired by the user, the selected server is determined as a DHCP server to receive a service (S440).

7 is a flowchart illustrating an embodiment of a method of selecting another DHCP server by changing a DHCP server currently being serviced. This is necessary to stop the service from the currently receiving DHCP server and to receive the service from another DHCP server before the length of lease expires.

First, receiving a DHCP server change command from the user (S500).

A parameter for a DHCP server currently receiving a service is stored in a desired DHCP parameter (S510). This is because, in the past, the user has selected the DHCP server that is currently receiving the service, it can be assumed that the parameter for this server will have the closest value to the desired parameter.

The DHCP server currently providing the service stops the service for the corresponding DHCP client and transmits a DHCPRELEASE message to provide the service to the other client (S520). DHCPRELEASE message is a message requesting the DHCP server to release the DHCP service.

After that, the method of selecting a DHCP server as shown in FIG. 3 is performed again.

The present invention can be embodied as code that can be read by a computer (including all devices having an information processing function) in a computer-readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording devices include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like.

Although the foregoing description has been described focusing on the novel features of the invention as applied to various embodiments, those skilled in the art to which the invention pertains have been described above without departing from the scope of the invention. It will be understood that various deletions, substitutions, and changes in form and details of the apparatus and methods are possible. Accordingly, the scope of the invention is defined by the appended claims. All modifications within the scope of equivalents of the claims are to be embraced within the scope of the present invention.

According to the method for selecting a DHCP server according to the present invention, by selecting a DHCP server that satisfies a desired parameter among a plurality of DHCP servers, even if a plurality of DHCP servers having various parameters exist on the network, It has the effect of letting you choose one. As a result, the DHCP client can selectively receive various DHCP services.

Claims (5)

(a) generating a DHCP server list including parameters related to a Dynamic Host Configuration Protocol (DHCP) server on the network; (b) comparing a DHCP server related parameter included in the DHCP server list with a DHCP parameter desired by the user to determine a DHCP server to request DHCP service; (c) transmitting a message requesting a DHCP service to the determined DHCP server; (d) waiting for the determined DHCP server to transmit a message approving a DHCP service for a predetermined time; And (e) if the DHCP server receives the message of approving the DHCP service from the determined DHCP server within the predetermined time, providing a network address included in the DHCP service approval message to a network interface. How to choose. The method of claim 1, If the DHCP message is not received from the determined DHCP server within the predetermined time, the DHCP server selection method of deleting a part of the DHCP parameter desired by the user and repeating from the step (b) again. According to claim 1, wherein the step (a), (a1) initializing the DHCP server list; (a2) transmitting a message to the network to find a DHCP server to be added to the DHCP server list, and waiting for a message for providing DHCP service from a DHCP server on the network for a predetermined time; (a3) storing the DHCP service providing message when receiving a message to provide DHCP service from at least one DHCP server within the predetermined time; And (a4) If the message for providing DHCP service is not received within the predetermined time, check whether the message for providing one or more DHCP services is stored, and if the message for providing one or more DHCP services is stored, provide the stored DHCP service. DHCP server selection method comprising the step of creating the DHCP server list by using a message. According to claim 1, wherein step (b), (b1) displaying the DHCP server list to a user; (b2) receiving a selection of one of the servers displayed in the DHCP server list from a user; (b3) setting parameters for the selected server to a DHCP parameter desired by the user; And (b4) determining the selected server as a DHCP server for requesting the DHCP service. The method of claim 1, Receiving a change command of a DHCP server from a user; Setting a parameter for a DHCP server currently providing DHCP service to a DHCP parameter desired by the user; And And transmitting a message requesting that the DHCP service be released to the DHCP server providing the DHCP service.

Images