KR20100011377A - Network apparatus having port auto-configuration function and method thereof - Google Patents

Abstract

PURPOSE: A network apparatus with an automatic port setting function and a method therefor are provided to guarantee a normal operation even though any port among ports of the network apparatus is connected to a WAN. CONSTITUTION: A detecting unit(134) detects a port connected to a WAN among ports based on a result about packet transmission through respective ports(102~110). A transceiving unit(170) transmits or receives a packet by using the detected port and the other ports as a WAN port and LAN ports respectively to support at least one between communication between a WAN and a LAN and communication between LANs. The fixed packet includes a DHCP(Dynamic Host Configuration Protocol) related packet and an ARP(Address Resolution Protocol) related packet.

Description

Network apparatus having port autoconfiguration function and method therefor {network apparatus having port auto-configuration function and method}

TECHNICAL FIELD The present invention relates to a network device, and more particularly, but not exclusively, to a network device having a port auto-configuration function and a method therefor.

Devices such as computers can perform internet-based communication using unique identification numbers called IP addresses. In general, these devices are assigned an IP address from an Internet Service Provider (ISP), which is called a public IP address.

On the other hand, for efficient and private use of such public IP addresses, IP routers are currently used in LANs. Depending on the point of view, IP routers, which are variously called broadband routers, residential gateways, cable / dsl routers, etc., convert one public IP address into one or more corresponding private IP addresses, or one or more private IP addresses. It translates into an address and connects WAN and LAN. Through this IP router, multiple devices can perform internet communication with one public IP address.

A general IP router has separate ports for connecting to the WAN (hereinafter referred to as WAN port) and ports for connecting to the LAN (hereinafter referred to as LAN port), and logic specialized for WAN related processing and logic related to LAN related processing are provided. It is implemented by connecting directly and indirectly to WAN port and LAN port respectively. Therefore, in order for the IP router to operate normally, the WAN port should be equipped with a cable connected to the WAN, and the LAN port should be equipped with a cable connected to the devices in the LAN.

Under this background, a normal installation of an IP router requires a minimum of knowledge and careful consideration of port connections for the IP router's port connection, which is a great burden for most users unfamiliar with network devices. .

An object of the present invention is to provide a network device having a port autoconfiguration function and a method therefor.

In order to achieve the above technical problem, a first aspect of the present invention provides a detection unit configured to detect a port connected to a WAN from among a plurality of ports based on a result of a predetermined packet transmission through each of a plurality of ports; And a transceiver for transmitting or receiving a packet by using the detected port and the remaining ports as WAN ports and LAN ports, respectively, to support at least one of communication between a WAN and a LAN and communication within the LAN. .

In order to achieve the above technical problem, a second aspect of the present invention is to (a) attempt to obtain an IP address by operating a Dynamic Host Configuration Protocol (DHCP) client for each of the plurality of ports. Making; (b) checking the number of ports for obtaining a public IP address according to the attempt of step (a); And (c) if the number of ports identified in step (b) is 1, determining a port that obtains a public IP address as a port connected to a WAN.

In order to achieve the above technical problem, a third aspect of the present invention provides an address resolution protocol for obtaining a MAC address of the gateway through each of the plurality of ports based on a preset IP address of the gateway. Resolution Protocol: Hereinafter, transmitting an ARP request packet; (b) checking the number of ports on which an ARP response packet from the gateway is received according to the transmission of step (a); And (c) if the number of the identified ports is 1, determining the port in which the ARP response packet is received as a port connected to the WAN.

Embodiments of the present invention presented above may have an effect including the following advantages. However, all the embodiments of the present invention are not meant to include them all, and thus the scope of the present invention should not be understood as being limited thereto.

According to an embodiment of the present invention, even if any of the ports of the network device (for example, the IP router) is connected to the WAN, it is possible to ensure the normal operation, thereby, WAN port and LAN port to configure a normal network It can reduce the user's hassle to check correctly.

Since descriptions of embodiments of the present invention are merely illustrated for structural to functional descriptions of the present invention, the scope of the present invention should not be construed as limited by the embodiments described in the present invention. That is, the embodiments of the present invention may be variously modified and may have various forms, and thus, it should be understood that the present invention includes equivalents capable of realizing the technical idea of the present invention.

On the other hand, the meaning of the terms described in the present invention will be understood as follows.

Terms such as "first" and "second" are intended to distinguish one component from another component, and the scope of the present invention should not be limited by these terms. For example, the first component may be named a second component, and similarly, the second component may also be named a first component.

The term “and / or” should be understood to include all combinations that can be presented from one or more related items. For example, "first item, second item, and / or third item" means "at least one or more of the first item, second item, and third item". A combination of all items that can be presented from two or more of the first, second and third items as well as the third item.

When a component is referred to as being "connected" to another component, it should be understood that there may be other components in between, although it may be directly connected to the other component. On the other hand, when a component is said to be "directly connected" to another component, it should be understood that there is no other component in between. On the other hand, other expressions describing the relationship between the components, such as "between" and "immediately between" or "neighboring to" and "directly neighboring to", should be interpreted as well.

Singular expressions described herein are to be understood to include plural expressions unless the context clearly indicates otherwise, and the terms "comprise" or "having" include elements, features, numbers, steps, operations, and elements described. It is to be understood that the present invention is intended to designate that there is a part or a combination thereof, and does not exclude in advance the possibility of the presence or addition of one or more other features or numbers, steps, actions, components, parts or combinations thereof. .

Each step described in the present invention may occur out of the stated order unless the context clearly dictates the specific order. That is, each step may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the reverse order.

Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and shall be interpreted as having ideal or overly formal meanings unless expressly defined in this application. Can't be.

The network device according to the present invention may be utilized as an IP router, but the scope of the present invention is not limited to the IP router.

1 is a block diagram showing the configuration of a network device according to an embodiment of the present invention.

Referring to FIG. 1, the network device 100 includes ports 102, 104, 106, 108, and 110, an I / O interface 120, a controller 130, a configuration information storage unit 140, and a virtual LAN ( Virtual Local Area Network (hereinafter, referred to as a VLAN) setting table 150 and a user interface 160.

A port arbitrarily selected by the user among the ports 102, 104, 106, 108, 100 and connected to the WAN, for example, the third port 106, is used as the WAN port, and the remaining ports such as the first, second, Four and five ports 102, 104, 108 and 110 are used as LAN ports.

Referring to FIG. 1, the controller 130 includes an I / O controller 132, a detector 134, and a UI controller 136.

For convenience of description, it is assumed that the third port 106 among the ports 102, 104, 106, 108, and 110 is arbitrarily selected by the user and is equipped with a cable connected to the WAN. An embodiment will be described.

The detector 134 is a port connected to a WAN among the ports 102, 104, 106, 108, and 110 based on a result of a predetermined packet transmission through each of the ports 102, 104, 106, 108, and 110. The third port 106 is detected.

According to one embodiment, the predetermined packet is a DHCP related packet. According to another embodiment, the predetermined packet is an ARP related packet. The detailed operation of the detector 134 will be described later.

Referring to FIG. 1, the I / O interface 120, the I / O control unit 132, and the VLAN setting table 150 form a transceiver 170, which is a detected port. Through the remaining ports 102, 104, 108, and 110 except for the three ports 106, a packet transmission and reception associated with a LAN is performed. Preferably, the transceiver 170 regards the third port 106, which is the detected port, as a port for the first VLAN, and the remaining ports 102, 104, 108, and 110 are ports for the second VLAN. In this case, packet transmission and reception are performed.

VLAN refers to a technique for grouping a plurality of nodes into a broadcast domain regardless of the physical location of network nodes. This VLAN technology improves security by restricting network resource access in groups and reduces the amount of broadcast traffic by reducing the size of the broadcast domain.

The VLAN configuration table 150 stores information about the relationships between the ports 102, 104, 106, 108, and 110 and the first and second VLANs. For example, if it is detected that the third port 106 is a port connected to the WAN, the detector 134 determines that the third port 106 belongs to the first VLAN, and the remaining ports 102, 104, 108, and 110 Information belonging to the second VLAN is stored in the VLAN setting table 150 in the above-described manner. In this case, when the broadcast data is received from the second port 104, the transceiver 170 checks the internal VLAN setting table 150 to confirm that the VLAN mapped to the second port 104 is the second VLAN. Thereafter, the received broadcast data is transmitted to the remaining ports 102, 108, and 110 belonging to the second VLAN.

2A and 2B illustrate the information stored in the VLAN configuration table 150.

Referring to FIG. 2A, it can be seen that VLAN 2 is mapped to the first, second, fourth, and fifth ports 102, 104, 108, and 110, and VLAN 1 is mapped to the third port 106.

2B, it can be seen that specific information of the corresponding port is mapped to each of the ports 102, 104, 106, 108, and 110. The information corresponding to FIG. 2B shows that the WAN port forms the first VLAN, and the LAN port 1, the LAN port 2, the LAN port 3, and the LAN port 4 form the second VLAN to form two different VLANs.

However, in addition to the above-described information, various forms, for example, mapping information between the port identifier and the address (eg, MAC address, IP address) of the device connected to the corresponding port 102, 104, 106, 108, 110, and port identifier Those skilled in the art can fully understand that the mapping information between the IP address and the subnet IP address formed by the corresponding ports 102, 104, 106, 108 and 110 can be used.

The I / O interface 120 may be subordinate to a packet received from each of the ports 102, 104, 106, 108, 110, or a packet for transmission to each of the ports 102, 104, 106, 108, 110. Perform layer processing. Here, the lower layer processed by the I / O interface 120 basically includes a physical layer, and may further include a data link layer (eg, including a media access control layer). It may further include. In general, the I / O interface 120 is implemented with hardware (eg, a chip) for processing the physical layer and the Media Access Control (MAC) layer, and the I / O control unit 132 may Although generally implemented to be operated by software for processing for the above layers (eg, network layers), the scope of the present invention is not necessarily limited thereto.

The I / O control unit 132 may be a layer higher than the layer processed by the I / O interface 120 (eg, a data link layer or higher, or a network layer to support communication between the WAN and the LAN and / or communication within the LAN). Function), the detected port, that is, the third port 106 is regarded as a WAN port, and the remaining ports 102, 104, 108 and 110 are regarded as LAN ports so that packet transmission or packet reception is performed. It has a function to control the / O interface 120.

The user interface 160 provides the user with information obtained from the network device 100 under a control of the UI controller 136 through a screen, a sound, an LED, and the like. Here, as an example of the provided information, as shown in FIG. 2B, the detection result of the detector 134, that is, the third port 106 is a port connected to the WAN, and the remaining ports 102, 104, 108, and 110 are LANs. For example, the port for. Examples of the information providing method may include a method of using a color display of LEDs that are mapped one-to-one to each of the ports 102, 104, 106, 108, and 110, a method of providing the information through an LCD screen, and other sounds, and the network apparatus 100. A method of transmitting the corresponding information to other devices of the user connected with the terminal is not limited thereto.

In addition, the user interface 160 provides the UI controller 136 with information input from the user (eg, keyboard input, button input, etc.). Here, an example of the input information may include setting information such as an IP address of a gateway, an IP address of a DNS server, and the like.

The setting information storage unit 140 stores the above-described setting information.

3 is a flowchart illustrating a method of operating a network device according to an embodiment of the present invention. This embodiment can be utilized in a dynamic IP address setting environment.

Referring to FIG. 1, the embodiment of FIG. 3 will be described.

When a predetermined event occurs, an operation according to the embodiment of FIG. 3 is performed. Here, an example of the predetermined event may include a case where a request for booting the network device 100 and information about a port connected to a WAN is requested from a user through the user interface 160, but is not limited thereto.

In operation S300, the detection unit 134 attempts to obtain an IP address by operating a DHCP client for each of the ports 102, 104, 106, 108, and 110. That is, an IP address acquisition process using DHCP is performed for all ports 102, 104, 106, 108 and 110. Here, those skilled in the art that the DHCP client function may be embedded in the controller 130 or implemented as a separate module, may be sufficiently understood.

When the detector 134 operates the DHCP client, the transceiver 170 transmits a DHCP discovery packet through all the ports 102, 104, 106, 108, and 110. In this case, at least one DHCP offer packet, which is a response packet to the DHCP discovery packet, is received at a port connected to the WAN, which is the third port 106, and, among other ports, among the remaining ports 102, 104, 108, and 110 due to other circumstances. At least one DHCP offer packet may be received in whole or in part. Here, as another example, at least one of the devices in the LAN connected to the remaining ports 102, 104, 108, and 110 has a DHCP server function.

Here, the DHCP offer packet includes an IP address.

For convenience, the first case did not receive the DHCP offer packet on all the ports 102, 104, 106, 108, 110, the second case received the DHCP offer packet only on the third port 106, and the third port ( 106 as well as the third case in which the DHCP offer packet is received at the fourth port 108 will be described below.

In the first case, since the IP address has not been allocated, the process proceeds to step S310 through step S310 and step S340. In this case, in step S354, the detection unit 134 determines the port having the highest priority as the port connected to the WAN, based on the priority information between the ports 102, 104, 106, 108, and 110 which are set in advance. . Here, as an example of how the detection unit 134 obtains the priority information, the priority information input by the user through the user interface 160 is stored in the setting information storage unit 140, and if necessary, the detection unit 134. ), A method of storing the priority information in advance in a separate memory provided in the network device 100, and reading by the detector 134 if necessary, but is not necessarily limited thereto.

In the second case, the DHCP request packet is transmitted through the third port 106 where the DHCP offer packet is received. Thereafter, a DHCP ACK packet, which is a packet in response thereto, is received at the third port 106. In the third case, the DHCP request packet is transmitted through the third and fourth ports 106 and 108 where the DHCP offer packet is received. Thereafter, a DHCP ACK packet, which is a packet in response thereto, is received at the third and fourth ports 106 and 108.

Here, the DHCP request packet includes an IP address selected by the DHCP client function among at least one IP address obtained by receiving at least one DHCP offer packet. In addition, the DHCP ACK packet indicating that the IP address included in the DHCP request packet is available includes information on the IP address of the DNS server.

In step S310, the detection unit 134 checks the number of ports assigned a public IP address. The second case is divided into CASE_2A = {third port: public IP address}, CASE_2B = {third port: private IP address}, and the third case is CASE_3A = {third port: public IP address, fourth port: public IP address}, CASE_3B = {third port: public IP address, fourth port: private IP address}, CASE_3C = {third port: private IP address, fourth port: public IP address}, CASE_3D = {third port : Private IP address, fourth port: private IP address}.

As an example of a situation where the third port 106 receives a private IP address, such as CASE_2B, CASE_3C, and CASE_3D, an IP router in which the network device 100 is located at the top of the network as the third port 106 (this IP router is a WAN) Connected to the In this case, a private IP address is assigned through the DHCP server function of the upper IP router.

An example of a situation in which the fourth port 108 receives a private IP address, such as CASE_3B and CASE_3D, may be a case in which the network device 100 is connected to the IP router in the LAN via the fourth port 108. In this case, the network device 100 is assigned a private IP address through the DHCP server function of the IP router.

Like CASE_3A and CASE_3C, a situation in which the fourth port 108 receives a public IP address rarely occurs, but for example, it is as follows. When the network device 100 is connected to the IP router in the LAN via the fourth port 108, and a public IP address is assigned to the network device 100 due to a malfunction or misconfiguration of the DHCP server function of the IP router. Can be mentioned.

If the number of ports assigned to the public IP address is 1 (S310), the detector 134 determines the port to which the public IP address is allocated, that is, the third port 106, as a port connected to the WAN (S312). CASE_2A and CASE_3B fall in this case. On the other hand, CASE_3C also corresponds to this case, a situation may occur where the fourth port 108 is determined to be a port connected to the WAN. However, since the probability that the third port 106 is assigned a private IP address and that the fourth port 108 is assigned a public IP address is small enough to ignore, the situation of CASE_3C can be ignored.

On the other hand, as an example of how to distinguish whether the assigned IP address is a public IP address or a private IP address, the detection unit 134 detects information on a typical private IP address (eg, 10.xxx, 172.xxx, 192.168.xx, etc.). After a) is provided in advance, there is a method for comparing the assigned IP address with the information provided, but there are various methods other than these methods, those skilled in the art can fully understand.

The detection unit 134 performs step S320 when the number of ports allocated with the public IP address is 2 or more (S310). CASE_3A is the case here.

The detection unit 134 performs step S340 when the number of ports assigned the public IP address is 0 (S310). CASE_3D corresponds to this.

In operation S320, the detection unit 134 may transmit the DNS server through a port receiving the DHCP ACK packet, for example, the third port 106 and the fourth port 108, based on the IP address of the DNS server obtained in operation S300. Send a response request packet. Here, the response request packet may include, but is not limited to, an Internet Control Message Protocol (ICMP) echo request packet, other query packet called Ping, and the like.

Here, in a general situation, since a response packet, for example, an IGMP echo response packet, will be received only at the third port 106, step S334 is performed. That is, in step S334, the detector 134 determines the third port 106 that receives the response packet as a port connected to the WAN.

In other cases, when the response packet is received from the fourth port 108 as well as the third port 106 (S330), step S336 is performed. That is, in operation S336, the detector 134 may perform the third port 106 on the basis of priority information between the ports 102, 104, 106, 108, and 110 set in advance in the configuration information storage 140. The higher priority among the fourth ports 108 is determined as a port connected to the WAN.

In operation S340, the detector 134 checks the number of ports allocated with the private IP address.

If the number of ports allocated with the private IP address is 1 (S340), the detector 134 determines the port assigned with the private IP address, that is, the third port 106 as a port connected to the WAN (S342). CASE_2B is the case here.

The detection unit 134 performs step S344 if the number of ports allocated with the private IP address is 2 or more (S340). CASE_3D is the case here.

In step S344, the detection unit 134, based on the IP address of the DNS server obtained in step S300, the DNS server through the port receiving the DHCP ACK packet, for example, the third port 106 and the fourth port 108 Send a response request packet. Here, an example of the response request packet is as described above. Here, in a general situation, since the response packet will be received only at the third port 106, step S352 is performed. In operation S352, the detector 134 determines the third port 106 that receives the response packet as a port connected to the WAN. In other cases, when the response packet is received from the fourth port 108 as well as the third port 106 (S350), step S354 is performed. That is, in operation S354, the detection unit 134 may take priority among the third port 106 and the fourth port 108 based on priority information between the preset ports 102, 104, 106, 108, and 110. The higher priority port is determined as the port connected to the WAN.

After the ports connected to the WAN are detected by steps S312, S334, S336, S342, S352, and S354, step S360 is performed.

In operation S360, the detector 134 stores the relationships between the ports 102, 104, 106, 108, and 110 and the first and second VLANs in the VLAN setting table 150 based on the detected result. The / O control unit 132 activates VLAN-based communication.

When VLAN-based communication is activated (ie, after the S360 step is performed), the transceiver 170 may detect the port, that is, the third port 106, to support communication between the WAN and the LAN and / or communication within the LAN. ) As the WAN port and the remaining ports 102, 104, 108, 110 as the LAN ports to perform packet transmission or packet reception.

In operation S370, the UI controller 136 provides the user with information about the WAN and the detected port, information about the relationship between the ports 102, 104, 106, 108, and 110, and the first and second VLANs. To control the user interface 160.

4 is a flowchart illustrating a method of operating a network device according to another embodiment of the present invention. This embodiment can be utilized in a fixed IP address setting environment.

Referring to FIG. 1, the embodiment of FIG. 4 will be described.

When a predetermined event occurs, an operation according to the embodiment of FIG. 4 is performed. Here, the predetermined event is as described above.

In operation S400, under the control of the detector 134, the transceiver 170 may be configured based on the IP address of the gateway stored in advance in the configuration information storage 140, and the ports 102, 104, 106, 108, and 110. Send an ARP request packet through each node. That is, this ARP request packet is a packet for obtaining the MAC address of the gateway.

In operation S410, the detection unit 310 checks the number of ports on which an ARP response packet from the gateway is received.

If the number of ports for which the ARP response packet is received from the gateway is 0 (S410), the flow proceeds to step S436. In this case, in step S436, the detection unit 134 may take priority among the ports 102, 104, 106, 108, and 110 based on priority information between the preset ports 102, 104, 106, 108, and 110. The port with the highest rank is determined as the port connected to the WAN.

If the number of ports in which the ARP response packet is received from the gateway is 1 (S410), the port in which the ARP response packet is received, for example, the third port 106, is determined as a port connected to the WAN (S412).

If the number of ports for which the ARP response packet is received from the gateway is 2 or more (S410), under the control of the detector 134, the transceiver 170 may control the ports for receiving the ARP response packet, for example, the third port 106. And through the fourth port 108, send a response request packet to the DNS server. Herein, the description of the response request packet is as described above, and the IP address of the DNS server required to transmit the response request packet is information stored in advance in the configuration information storage 140.

In operation S430, the detector 134 checks the number of ports that have received a response from the DNS server.

Here, in a general situation, since the response packet from the DNS server will be received only at the third port 106, step S434 is performed. That is, in step S434, the detector 134 determines the third port 106 that receives the response packet as a port connected to the WAN.

In other cases, when the response packet is received from the fourth port 108 as well as the third port 106 (S430), step S436 is performed. In this case, in operation S436, the detector 134 may set the third port 106 based on priority information between the ports 102, 104, 106, 108, and 110 set in advance in the configuration information storage 140. And a higher priority port of the fourth port 108 as a port connected to the WAN.

After the ports connected to the WAN are detected by steps S412, S434, and S436, step S460 is performed.

In operation S460, the detector 134 stores the relationships between the ports 102, 104, 106, 108, and 110 and the first and second VLANs in the VLAN setting table 150 based on the detected result. The / O control unit 132 activates VLAN-based communication.

In operation S470, the UI controller 136 provides the user with information about the WAN and the detected port, information about the relationship between the ports 102, 104, 106, 108, 110, and the first and second VLANs. To control the user interface 160.

The invention can also be embodied as computer readable code on a computer readable recording medium. Computer-readable recording media include all kinds of recording devices that store data that can be read by a computer system. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like, which are also implemented in the form of carrier waves (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. In addition, functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers in the art to which the present invention belongs.

Such a method and apparatus of the present invention have been described with reference to the embodiments shown in the drawings for clarity, but these are merely exemplary, and various modifications and equivalent other embodiments are possible to those skilled in the art. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

Embodiments of the present invention presented above may have an effect including the following advantages. However, all the embodiments of the present invention are not meant to include them all, and thus the scope of the present invention should not be understood as being limited thereto.

According to an embodiment of the present invention, even if any of the ports of the network device (for example, the IP router) is connected to the WAN, it is possible to ensure normal operation, thereby, WAN-related ports and LAN to configure a normal network This saves users the trouble of having to check the relevant ports.

1 is a block diagram showing the configuration of a network device according to an embodiment of the present invention.

2A and 2B illustrate the information stored in the VLAN configuration table.

3 is a flowchart illustrating a method of operating a network device according to an embodiment of the present invention.

4 is a flowchart illustrating a method of operating a network device according to another embodiment of the present invention.

Claims (17)

A network device comprising a plurality of ports, A detector configured to detect a port connected to a WAN among the plurality of ports based on a result of a predetermined packet transmission through each of the plurality of ports; And And a transceiver for transmitting or receiving a packet by using the detected port and the remaining ports as WAN ports and LAN ports, respectively, to support at least one of communication between a WAN and a LAN and communication within the LAN. . The method of claim 1, wherein the predetermined packet is And a DHCP related packet and an ARP related packet. The method of claim 1, wherein the transceiver unit Consider the detected port as a port for a first VLAN, and consider the remaining ports as ports for a second VLAN to perform packet transmission and reception. The method of claim 3, wherein the transceiver unit, A VLAN configuration table for storing a relationship between the plurality of ports and the first and second VLANs; An I / O interface performing lower layer processing on a packet received from each of the plurality of ports or a packet for transmission to each of the plurality of ports; And An I / O control unit for controlling the I / O interface to perform VLAN-based packet transmission and reception, And wherein said lower layer processing comprises at least physical layer processing. The method according to any one of claims 1 to 4, And a user interface for providing a user with information about the detected port. The said detection part is a any one of Claims 1-4. And detecting a port connected to a WAN based on a result obtained by attempting an IP address obtaining process using DHCP for each of the plurality of ports. The method according to any one of claims 1 to 4, Further comprising a setting information storage for storing the setting information including the IP address of the gateway, The detecting unit detects a port connected to a WAN based on receiving an ARP response packet generated after transmitting an ARP request packet of the gateway to each of the plurality of ports. The method according to any one of claims 1 to 4, And said network device comprises an IP router. In the operating method of a network device including a plurality of ports, (a) attempting to obtain an IP address by operating a DHCP client for each of the plurality of ports; (b) checking the number of ports for obtaining a public IP address according to the attempt of step (a); And (c) if the number of ports identified in step (b) is 1, determining a port that obtains a public IP address as a port connected to a WAN. The method of claim 9, (d) if the number of ports identified in step (b) is plural, transmitting a packet requesting a response to a DNS server through each of the ports for obtaining the public IP address; And (e) determining the port in which the response is received from the DNS server as a port connected to the WAN. The method of claim 10, (f) if the number of ports identified in step (b) is 0, checking the number of ports for obtaining a private IP address according to the attempt of step (a); And and (g) if the number of ports identified in step (f) is 1, determining a port obtained by obtaining a private IP address as a port connected to a WAN. The method of claim 11, (h) if the number of ports identified in step (f) is plural, transmitting a packet requesting a response to a DNS server through each of the ports assigned a private IP address; And and (i) determining the port that has received the response from the DNS server as a port connected to the WAN according to the transmission of step (h). The method according to any one of claims 9 to 12, Sending or receiving a packet using the detected port and the remaining ports as WAN port and LAN ports, respectively, to support at least one of communication between a WAN and a LAN and communication within the LAN. How the device works. In the operating method of a network device including a plurality of ports, (a) transmitting an ARP request packet for obtaining a MAC address of the gateway through each of the plurality of ports based on a preset IP address of the gateway; (b) confirming the number of ports on which an ARP response packet from the gateway was received according to the transmission in step (a); And and (c) if the number of the identified ports is 1, determining the port in which the ARP response packet is received as a port connected to the WAN. The method of claim 14, (d) if the number of the identified ports is plural, transmitting a packet requesting a response to the DNS server through each of the ports on which an ARP response packet from the gateway is received, based on a preset IP address of the DNS server. step; And (e) determining the port receiving the response from the DNS server as a port connected to the WAN. The method according to claim 14 or 15, Sending or receiving a packet using the detected port and the remaining ports as WAN port and LAN ports, respectively, to support at least one of communication between a WAN and a LAN and communication within the LAN. How the device works. The method according to claim 14 or 15, And providing information on the determined port to a user.

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