KR100960794B1 - Apparatus and method for identifying failed access point in wireless local area network - Google Patents

Abstract

The present invention relates to a bad access point identification apparatus and method in a wireless Internet access environment in which a bad access point is identified by testing whether the access point is normally operated through an identification device that can access the wireless Internet.

To this end, the present invention is a MAC address extraction unit for extracting the MAC address of the access point; An address automatic setting unit for allocating an IP address from a DHCP server using the extracted access point's MAC address to perform network setting; An IP address extractor configured to extract an IP address of the access point using the extracted MAC address of the access point; A default routing checker for checking default routing information of the access point using the extracted access point's IP address; An interface unit for discovering an access point and informing the MAC address extracting unit to control data transmission and reception of the MAC address extracting unit, the address automatic setting unit, the IP address extracting unit, and the default routing check unit; And determining that the access point is a bad access point when the network setting cannot be performed because there is no response from the DHCP server, when the IP address of the access point cannot be extracted, and when there is no default routing information of the access point. It is characterized in that the automatic identification of whether the access point is defective by connecting directly through the access point in a wireless Internet connection environment.

Description

Apparatus and method for identifying failed access point in wireless local area network

1 is a block diagram of a network for a general wireless Internet access.

2 is an internal configuration diagram of a bad AP identification device according to the present invention.

3 is a flowchart of a method for identifying a bad AP by the bad AP identification device according to the present invention;

4 is a view showing the format of the RARP message transmitted to the AP in the bad AP identification apparatus according to the present invention.

5 is a view of the content of the IP packet to query the default routing information to the AP in the rogue AP identification device according to the present invention.

FIG. 6 is the contents of an IP packet sent from the AP to the failing AP identification device according to the present invention in response to FIG. 5; FIG.

The present invention relates to an apparatus and method for identifying a rogue access point in a wireless internet access environment. More particularly, the present invention relates to a rogue internet access point for identifying a rogue access point by testing whether the access point is normally operated through an apparatus for accessing the wireless internet. An apparatus and method for identifying a rogue access point in a connected environment.

As computers become smaller and terminals such as notebook computers and PDAs (Personal Digital Assistants) are wirelessly connected to the Internet, wireless Internet access services are commercialized and provided to users. In order to provide a wireless Internet service, a network operator establishes a network by connecting various network devices. One of the key devices required for building such a wireless Internet is a wireless access device called an access point (hereinafter referred to as an AP).

The AP provides a function similar to a base station for a wireless Internet terminal like a base station of a mobile communication network. However, the characteristics such as frequency band, power, and coverage are very different from those of base stations in mobile communication networks. In particular, since the AP provides coverage within a radius of 100 m due to its low power, many APs are required to be installed compared to a mobile communication network.

The AP installed for the network is configured with an IP (Internet Protocol) address, a service identifier, and a server to which the wireless terminal first connects. The IP address of the AP is registered and operated in the network management system. When the AP is installed and the service is in the range of service, the user's wireless terminal is automatically assigned an IP through the AP, and the user's authority is verified so that the user can use the Internet wirelessly.

1 is a block diagram of a network for a general wireless Internet access.                         

The wired Internet 600 includes a DHCP (Dynamic Host Configuration Protocol) server 90 which automatically assigns and manages the IP addresses of the routers 70 and 80 and the terminals 2, 4 and 6. AP (10, 20, 30, 40, 50) is a component for providing a wireless Internet access service, performs a function similar to a base station of a mobile communication network, each AP is a service that can provide a wireless Internet access service The area is determined by the feature. The APs can provide wireless Internet access service in each of AP 10, AP 20, 200, AP 30, 300, AP 40, and AP 50, respectively. Provide internet access service.

The existing wired Internet 600 is configured by wires from the routers 70 and 80 to the terminal. Wireless Internet uses a wireless communication technology as a method of configuring the router (70, 80) to the AP (10, 20, 30, 40, 50) by wire, and the terminal in a network configuration. Since data transmitted and received between the AP 10, 20, 30, 40, 50 and the terminal are broadcasted in the air using radio waves, for example, the data provided by the AP 10 may be transmitted to the terminals 2, 4, 6. All are sent. When the APs are located in close proximity to each other and the wireless Internet service areas provided by the APs overlap (AP 10 and 20), in this area (100, 200), a plurality of APs (10, 20) are used for the terminal to use the Internet. ) Must be selected. To this end, the AP sets a service set identifier (SSID), which is a name of a network for wirelessly using the Internet. The SSID is used when the network is divided into segments, and the SSID may be, for example, 'Nespot'.

In the drawing, if the wireless Internet service area is overlapped (100, 200) and the terminals 2, 4, and 6 need to select the AP as one of 10 and 20, the terminals 2, 4, and 6 select the AP 10. You can use the wireless Internet service, but if you select AP 20, you cannot use the wireless Internet service. This is because the AP 10 is connected to the router 70 constituting the wired Internet 600 to transmit data of the wireless terminals 2, 4, 6 to the wired Internet 600, but the AP 20 is wired Internet 600. This is because the data of the terminal in the 200 area cannot be transmitted to the wired Internet 600 because it is not connected. Similarly, since the AP 50 is not connected to the wired Internet 600, the area 500 cannot provide a wireless Internet service.

On the other hand, in the wireless Internet service area, the wireless terminal should provide a function of automatically setting the IP address. There are two ways to assign an IP address: the user sets the IP address on the terminal and the IP address is automatically set on the terminal. The method of setting the IP address is mainly applied on the wired Internet. Since the network can be accessed while moving, the method of automatically setting an IP address in the terminal is used. The reason why the IP address is automatically set in the wireless Internet is that the user cannot obtain information for setting the IP address in the terminal when the user moves and accesses another network. IP address setting of such a terminal is performed through a DHCP server in the wired Internet.

In the drawing, AP 10 is connected to DHCP server 90 through router 70, but AP 30 and 40 are connected to router 80 but not to DHCP server 90. It is not possible to allocate IP addresses for using the Internet to terminals and to provide wireless Internet services. In this case, in order to use the wireless Internet in the area 300 or 400, the user needs to receive network information necessary for accessing the Internet from the person in charge of the AP in order to set the IP address.

As described above, in FIG. 1, APs 20, 30, 40, and 50 may not provide wireless Internet services even when the terminal is located in a communication area. And AP 10, 30, and 40 connected to the wired Internet 600 can be managed through a network management system by an operator providing a wireless Internet service, but AP 20 and 50 are not connected to the wired Internet 600. Therefore, there is a problem that is difficult to manage with a network management system. In addition, the AP 10, 30, and 40 that can be managed by the network management system has a problem that it is difficult to collect information to determine which of these is suitable for providing wireless Internet service.

In order to solve the above problems, an object of the present invention is to identify a rogue AP by testing whether the AP is operating normally through an identification device that can access the wireless Internet.

Another object of the present invention, to determine whether the AP is connected to the wired Internet to identify a bad AP.

It is still another object of the present invention to determine a bad AP by determining whether to perform an IP address setting function in a wireless terminal in an AP.                         

Another object of the present invention is to identify a bad AP by determining whether to provide a wireless Internet access service using the default routing information of the AP.

To this end, the present invention is a MAC address extraction unit for extracting the MAC address of the access point; An address automatic setting unit for allocating an IP address from a DHCP server using the extracted access point's MAC address to perform network setting; An IP address extractor configured to extract an IP address of the access point using the extracted MAC address of the access point; A default routing checker for checking default routing information of the access point using the extracted access point's IP address; An interface unit for discovering an access point and informing the MAC address extracting unit to control data transmission and reception of the MAC address extracting unit, the address automatic setting unit, the IP address extracting unit, and the default routing check unit; And determining that the access point is a bad access point when the network setting cannot be performed because there is no response from the DHCP server, when the IP address of the access point cannot be extracted, and when there is no default routing information of the access point. With wealth,

In the wireless Internet access environment, it is characterized by automatically identifying whether the access point is defective by accessing it directly through the access point.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is characterized in that the bad AP identification device directly accesses the AP in a wireless Internet access environment, and identifies the bad AP. FIG. 2 shows an internal configuration diagram of the bad AP identification device.

As illustrated, the bad AP identification device includes an interface unit 21, a default routing checker 22, an IP address extractor 23, a MAC (Media Access Control) address extractor 24, and an automatic address setting unit 25. And the AP determining unit 26.

The interface unit 21 communicates with the default routing checker 22, the IP address extractor 23, the MAC address extractor 24, and the automatic address setting unit 25 to transmit and receive data required to identify a bad AP. To control.

The MAC address extraction unit 24 extracts the MAC address of the AP, and the automatic address setting unit 25 automatically sets the IP address of the rogue AP identification device according to the present invention in association with the DHCP server.

The IP address extractor 23 extracts the IP address of the AP using the MAC address of the AP extracted from the MAC address extractor 24, and the default routing checker 22 extracts the IP address from the IP address extractor 23. By acquiring the default routing information of the AP by using the IP address of the AP, the bad AP identification apparatus according to the present invention checks whether data can be transmitted to the Internet through the AP.

The AP determining unit 26 is interworking with the default routing checker 22, the IP address extracting unit 23, and the automatic address setting unit 25, and there is no IP address of the AP or the IP of the bad AP identifying apparatus according to the present invention. The bad AP is identified when the address cannot be set or there is no default routing information of the AP. On the other hand, the AP determination unit 26 is implemented to enable comprehensive management of the AP in the management system by transmitting information on whether the AP is defective through interworking with the management system of the wireless Internet access service through the interface unit 21. desirable.

A method of identifying a bad AP by the bad AP identifying apparatus as described above will be described in detail with reference to FIG. 3.

First, when the power of the bad AP identification apparatus according to the present invention is turned on to find a bad AP, the interface unit 21 discovers the AP by checking whether there is an AP in a radius that can be connected to the surrounding (S2).

There are two ways to find an AP. The first is a passive method of waiting for the interface unit 21 to receive a signal from the AP. The AP transmits a signal called 'beacon' to the terminal at intervals of several tens of microseconds, and the network operator may set a transmission period of the beacon signal to a desired value. A passive method of discovering APs discovers APs from these beacon signals. The beacon message includes information such as Timestamp, Beacon Interval, Capability Information, SSID, Supported Rate, FH Parameter Set, DS Parameter Set, CF Parameter Set, IBSS Parameter Set, TIM (Traffic Indication Message).

Another method of discovering the AP is to transmit a probe request message to discover the AP in the interface unit 21 in an active manner. When the AP is located around the terminal to receive the probe message, the AP sends a probe response message and the interface unit 21 discovers the AP from the probe response message. The probe request message includes SSID and Supported Rate information, and the probe response message includes information excluding TIM information from the beacon message.

As described above, when the interface unit 21 detects the AP from the beacon message or the probe message, the interface unit 21 transfers the message to the MAC address extractor 24, and the MAC address extractor 24 receives the MAC address of the AP from the message. Extract (S4). The MAC address of the AP is extracted from the SSID information of the message.

The MAC address of the AP extracted from the MAC address extraction unit 24 is transmitted to the address automatic setting unit 25, the address automatic setting unit 25 is the IP of the bad AP identification device in order to identify whether the AP is connected to the wireless Internet Attempt to set the address. That is, the automatic address setting unit 25 uses the MAC address of the AP extracted from the MAC address extractor 24 to automatically configure the IP address of the bad AP identification device in the network with a DHCP server. An IP address for identification, a subnet mask indicating a network range, a bad AP identification device requests an IP address of a router to transmit a packet, and an address of a DNS server for identifying an opposite host by name (S6). At this time, since the bad AP identification device does not have an IP address, the source address is 0.0.0.0 and the destination address for specifying the DHCP server is 255.255.255.255.

In response to the DHCP request message, when the DHCP server sends an IP address, subnet mask, router IP address, and DNS server address to be used by the bad AP identification device, the automatic address setting unit 25 automatically sets the IP address of the bad AP identification device using the information (S8). That is, the network environment of the bad AP identification device is set.                     

If there is no response to the DHCP request message, the automatic address setting unit 25 sets the source address to 0.0.0.0 and the destination address for specifying the DHCP server to 255.255.255.255. Send (S10). If the DHCP server is found, the automatic address setting unit 25 performs the above-described step S6 and S8 to set the network environment of the bad AP identification device. However, if a DHCP server is not found, the automatic address setting unit 25 forwards the corresponding information to the AP determining unit 26 so that the AP determining unit 26 does not automatically set an IP address to the bad AP identification device. It may be determined that the bad AP having a cause of not being able to perform a wireless Internet access (S12).

On the other hand, after completing the network configuration process of the bad AP identification device by setting the IP address, the IP address extractor 23 sends a Reverse Address Resolution Protocol (RARP) message to the AP to extract the IP address of the AP (S14). . The format of the RARP message is shown in FIG. 4, where the hardware type of the RARP message indicates an Ethernet or IEEE 802 value, the protocol type indicates an IP of 0x800, and the hardware address length of the MAC. Length) uses 48 bits, the protocol address length of the IP is 32 bits, and if the OP code value is 3, the request message is transmitted to the AP from the IP address extraction unit 23 in the present invention. When the OP code value is 4, the present invention is used as a response message when the AP is transmitted from the AP to the IP address extractor 23. The source / destination hardware address uses a 48-bit MAC address. The source / destination protocol address uses a 32-bit IP address.

That is, the RARP request message transmitted from the IP address extraction unit 23 to the AP includes a hardware type of Ethernet or IEEE 802 value, a protocol type of IP, a hardware address length of 48 bits, a protocol address length of 32 bits, and an OP code. Request (3), the source hardware address is the 48-bit MAC address of the rogue AP identification device, the source protocol address is the 32-bit IP address of the rogue AP identification device set in step S8, and the destination hardware address is the 48-bit of the AP extracted in step S4. Contains the MAC address. In response to the RARP request message, the AP transmits the RARP response message to the IP address extractor 23 when the destination hardware address of the received message is the same as its MAC address. The RARP response message is an Ethernet or IEEE 802 value for hardware type, IP for protocol type, 48 bits for hardware address length, 32 bits for protocol address length, response (4) for OP code, and 48 bits MAC for source hardware address. Address, the source protocol address is the 32-bit IP address of the AP, the destination hardware address is the 48-bit MAC address of the bad AP identification device obtained in the RARP request message, and the destination protocol address is 32 of the bad AP identification device obtained in the RARP request message. Contains a bit IP address.

At this time, if the IP address extraction unit 23 does not receive a response message from the AP and extracts the IP address of the AP, the IP address extraction unit 23 transmits the corresponding information to the AP determination unit 26, and the AP determination unit 26. ) Allows the AP to be determined to be a rogue AP without an IP address (S12).

After extracting the IP address of the AP, the default routing checker 22 checks whether data can be transmitted to the Internet through the AP. That is, the default routing information of the AP is inspected using the Simple Network Management Protocol (SNMP) (S16). The default routing checker 22 may obtain various information about the AP by using such an SNMP message. However, in the present invention, when the rogue AP identification device wirelessly accesses the Internet, whether the path for transmitting data to the Internet exists. Used to check. To this end, the default routing checker 22 needs to know the IP address of the AP to be used in SNMP and OID (Object Identifier) information for querying the default routing information. The IP address of the AP uses the IP address extracted in step S14 described above. For the OID, it is preferable to use 'ipRouteNextHop.0.0.0.0', for example.

FIG. 5 shows the contents of an IP packet for inquiring default routing information from the default routing checker 22 to the AP, and FIG. 6 shows the contents of an IP packet sent to the default routing checker 22 from the AP. 5 and 6 show that when the IP address of the bad AP identification device is 147.6.75.21 and the IP address of the AP is 203.255.252.100 (51, 61), the default routing information is 'ipRouteNextHop.0.0.0.0' as the OID. In this example, the IP address 203.255.252.97 is collected (63).

When the default routing checker 22 collects the default routing information from the AP, the default routing checker 22 transmits the information to the AP determining unit 26 so that the AP determining unit 26 can normally provide the wireless Internet access service. It is determined to be (S18). On the other hand, when the default routing information value is not received from the AP, the default routing checker 22 transmits the information to the AP determining unit 26, causing the AP determining unit 26 to have a bad AP having no routing path. To be determined as (S12).

As described above, the present invention is characterized by identifying a bad AP by testing the AP in an environment of a general wireless terminal that can receive a wireless Internet access service using a bad AP identification device.

In addition, it is preferable that the apparatus for identifying a rogue AP according to the present invention is implemented so that the AP can be comprehensively managed in the management system by transmitting information on whether the AP is defective in association with the management system of the wireless Internet access service. The interworking may use a method of transmitting the identification information of the AP, which has been collected since the previous interworking, to the management system when the bad AP identification device identifies the AP, or transmits it through the normal AP at regular intervals. have.

As described above, the present invention has an effect of automatically identifying whether an AP is defective by automatically accessing the AP through a direct identification device in a wireless Internet connection environment and automatically classifying the cause of various defects.

In addition, in conjunction with the management system of the wireless Internet access service has the effect of efficiently supporting the network management of the service provider, thereby improving the technical reliability of the service.

Claims (14)

A MAC address extraction unit for extracting the MAC address of the access point; An address automatic setting unit configured to perform network setting by receiving an IP address from a DHCP server using the extracted MAC address of the access point; An IP address extractor configured to extract the IP address of the access point using the extracted MAC address of the access point; A default routing checker for checking default routing information of the access point using the extracted access point's IP address; An interface unit for discovering the access point and informing the MAC address extracting unit to control data transmission and reception of the MAC address extracting unit, the automatic address setting unit, the IP address extracting unit, and the default routing check unit; And When the network setting cannot be performed because there is no response from the DHCP server, when the IP address of the access point cannot be extracted, and when there is no default routing information of the access point, the access point is determined as a bad access point. An access point determination unit to And an access point identification device in a wireless Internet access environment, characterized in that the access point is automatically identified by connecting directly through the access point in a wireless Internet access environment. The method of claim 1, The address automatic setting unit, Request information necessary for the network setting from the DHCP server with a source address of 0.0.0.0 and a destination address of 255.255.255.255, The apparatus for identifying a bad access point in a wireless Internet access environment, wherein the DHCP server receives information including the IP address, the subnet mask, the router IP address, and the DNS server address. The method of claim 1, The IP address extraction unit, Apparatus for identifying a bad access point in a wireless Internet access environment, characterized in that for extracting the IP address of the access point by transmitting a RARP message including the extracted MAC address of the access point to the access point. The method of claim 1, The default routing checker, The bad access point in the wireless Internet access environment, characterized by requesting the default routing information of the access point using the SNMP message including the IP address and OID information of the extracted access point and receiving the default routing information as a response. Identification device. The method of claim 4, wherein The default routing checker, An apparatus for identifying a rogue access point in a wireless Internet access environment, wherein ipRouteNextHop.0.0.0.0 is used as the OID. The method according to any one of claims 1 to 5, The access point determination unit, And an access point identification device in a wireless Internet access environment, wherein the access point is managed in association with a management system of the network. In the bad access point identification method of the apparatus for automatically identifying whether the access point is defective by connecting through a direct access point in a wireless Internet connection environment, Extracting the MAC address of the access point when the access point is found; A second process of performing network configuration by receiving an IP address from a DHCP server using the extracted MAC address of the access point; A third step of extracting the IP address of the access point by using the extracted MAC address of the access point; A fourth step of checking default routing information of the access point by using the extracted IP address of the access point; And When the network setting cannot be performed because there is no response from the DHCP server, when the IP address of the access point cannot be extracted, and when there is no default routing information of the access point, the access point is determined as a bad access point. And a fifth step of performing a bad access point identification method in a wireless Internet access environment. The method of claim 7, wherein And if there is no response from the DHCP server, transmitting the DHCP server discovery message, and if the DHCP server is found, further comprising a sixth process of returning to the second process. Identification method. The method of claim 7, wherein And performing a network setting, extracting an IP address of the access point, and then obtaining default routing information of the access point, determining that the access point is a normal access point. How to identify rogue access points in an Internet connection environment. The method of claim 7, wherein The second process, Request information necessary for the network setting from the DHCP server with a source address of 0.0.0.0 and a destination address of 255.255.255.255, And receiving information including the IP address, subnet mask, router IP address, and DNS server address from the DHCP server. The method of claim 7, wherein The third process, And extracting an IP address of the access point by transmitting a RARP message including the extracted MAC address of the access point to the access point. The method of claim 7, wherein The fourth process, Bad access in a wireless Internet access environment, characterized by requesting the default routing information of the access point by using an SNMP message including the IP address and OID information of the extracted access point and receiving the default routing information as a response. Point identification method. The method of claim 12, The fourth process, The rogue access point identification method in a wireless Internet access environment, characterized in that using the IPRouteNextHop.0.0.0.0 as the OID. The method according to any one of claims 7 to 13, And an eighth process of interworking with the management system of the network and providing the access point whether the access point is defective or not.

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