JPH09266477A - Method for duplicate ip address detection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce man-hours to find out duplicate IP address by analyzing an object IP address so as to detect general terminals whose IP addresses are in duplicate thereby easily locating the terminals having duplicate an IP address. SOLUTION: Other terminals on a LAN system than a terminal desired to be investigated are started without parameters to set them to be general terminals 20. Then the remaining terminal is started with parameters to be selected as a duplication analysis terminal 10. A reply message transmission function 22 sends information of the general terminals 20 required for duplicate analysis of an IP address to the duplicate analysis terminal 10 via a LAN adaptor card 23. A reply message reception function 12 of the duplication analysis terminal 10 receives information from all the general terminals 20 to shift the control to a table generation/analysis function 13 and duplication analysis of the IP address is conducted based on information in a table and the result is given to an analysis result display function 14 to display a general terminal whose IP address is in duplicate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting duplicate IP addresses in a LAN system that sets IP addresses for each terminal.

[0002]

2. Description of the Related Art As is well known, in a LAN system using the TCP / IP protocol, an M unique to each terminal is used.
AC address (Media Access Controller)
LAN adapter card with an IP address (Inol.
Internet Protocol address),
In data communication, an IP address and a MAC address are added to a communication text and transmitted.

Here, since the MAC address is provided by, for example, a ROM in which a unique value is written, it does not overlap between terminals. However, the IP address is L
Since the administrator of the AN system determines it, distributes it to the user of each terminal, and sets it in his own terminal by each user, there is a possibility of duplication due to an error of the administrator or the user.

Conventionally, when a duplicate IP address is detected due to such a cause, the IP address set in each terminal is referred to or compared with each other, or the terminals which seem to be duplicate are simultaneously communicated with each other to detect a failure. There was a method of specifying by generating.

[0005]

However, if an attempt is made to detect a duplicate IP address by the above method,
The following problems occur. That is, 1. When the failure is detected before the IP address duplication occurs, the work man-hour increases in proportion to the number of connected terminals, and it is difficult to identify the duplicated terminals.

[0006] 2. Moreover, when visually confirming, human error such as omission of check may occur.

The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to easily
It is an object of the present invention to provide a duplicate IP address detection method that can identify a terminal having a duplicate IP address and reduce the man-hours spent for this work.

[0008]

In order to achieve the above-mentioned object, the present invention sets one terminal in a LAN system as an IP address duplication analysis terminal and the other as a general terminal for the IP address duplication analysis. An IP address reply request is issued from the terminal to the general terminal, the general terminal returns the IP address of each general terminal, and the returned IP
It is characterized in that a table of addresses is created, and the IP addresses in the table are analyzed to detect and display general terminals with overlapping IP addresses.

Here, the duplication analysis terminal and the general terminal are set, for example, by the presence / absence of a parameter at the time of startup. If there is a parameter, the duplication analysis terminal is set.

Further, the IP address reply request is transmitted by a broadcast type message which can identify that the purpose is duplicate analysis.

Further, the general terminal sends back the MAC address in addition to the IP address, and the duplication analysis terminal uses the IP address.
General terminals with the same address but different MAC addresses,
It is specified and displayed as a general terminal having a duplicate IP address.

Therefore, since the IP addresses set in each general terminal are automatically collected, it is not necessary to manually check for each general terminal whether or not the IP addresses are duplicated. Further, since the collected IP addresses are analyzed to identify and display the duplicate general terminals, human error does not occur.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a system configuration diagram showing an embodiment of a LAN system to which the duplicate IP address detection method of the present invention is applied.

In FIG. 1, 10 is a duplication analysis terminal, 2
0 is a general terminal.

The duplication analysis terminal 10 includes a broadcast transmission function 11, a response message reception function 12, a table creation / analysis function 13 and an analysis result display function 14, LA.
The general terminal 20 has an N adapter card 15 and a message receiving function 21, a response message sending function 22 and a LAN adapter card 23.

The duplication analysis terminal 10 and the general terminal 20 are distinguished from each other by, for example, the presence or absence of a parameter at the time of activation. If there is a parameter, the duplication analysis terminal 10 is set.

The LAN adapter cards 15 and 23 are
It corresponds to the interface with the LAN line network, and a unique MAC address is written in the ROM of this card. At the time of data transmission, this MAC address and the IP address set in each terminal Is added to the message and transmitted.

In this configuration, first, the LA to be investigated
Other than one terminal on N system (other than duplicate analysis terminal 10)
The terminal is set up as a general terminal 20 by starting the terminal without any parameters, and the message receiving function 21 is made to wait in the message waiting state.

Next, the remaining one terminal is set up as a duplicate analysis terminal 10 by starting it with parameters, and the LAN adapter card 15 is met by the broadcast transmission function 11 to receive the message reception function 21 of the general terminal 20.
To send a message to.

The message receiving function 21, which has been waiting in the message waiting state, transfers control to the response message transmitting function 22 if the message is from the broadcast transmitting function 11.

The response message sending function 22 sends the information of the general terminal 20 necessary for the IP address duplication analysis to the duplication analysis terminal 10 through the LAN adapter card 23.

The response message receiving function 12 of the duplication analysis terminal 10 receives information from all the general terminals 20 and transfers control to the table creation / analysis function 13.

The table creation / analysis function 13 creates a table of information received from all general terminals 20, performs IP address duplication analysis based on the information in the table, and passes the result to the analysis result display function 14. Display a general terminal with a duplicate IP address.

The details will be described below with reference to FIGS.

FIG. 2 is a flowchart showing a duplicate IP address detection procedure.

Duplication analysis terminal 10 and general terminal 20
When each is activated, it determines whether or not there is a parameter at the time of activation (step 101).

If it is determined that there is no parameter, it corresponds to the general terminal 20 and therefore the message reception waiting state is set (step 110).

On the other hand, if it is determined that there is a parameter, it corresponds to the duplication analysis terminal 10, so the validity check is performed to see if the parameter is a number (the number of terminals to be analyzed) (step 102).

Next, the result of the parameter validity check is determined, and if it is determined that there is an error, the duplicate IP address analysis process is terminated (step 103).

If there is no error, the duplication analysis terminal 10 sends a broadcast type message including an ID that can identify that duplication analysis is intended to all general terminals 20 (step 104).

Then, the system waits to receive a reply message from the general terminal 20 (step 105).

On the other hand, the general terminal 20 waiting for message reception
When receiving this broadcast method message, the
Information such as an address is transmitted as a reply message (step 111).

Here, if it is determined that the received message includes the keyword indicating the end instruction, the duplicate IP address analysis processing ends, but if the keyword is not included, the process returns to step 110 again. A message waiting state is entered (step 112).

Duplication analysis terminal 10 in the message waiting state
When receiving the reply message from the general terminal 20,
It counts up as the number of received messages, and in the case of the first case, the table 31 shown in FIG. 3 is set to 0, and the IP address and the MAC address are paired based on the reply message.
A record is added in the format as shown in FIG. 3 (step 106).

Next, the parameter passed at the time of activation (the number of terminals to be analyzed) is compared with the number counted as the number of received messages, and if the parameter is larger, the general terminal that has not yet received the reply message. Since 20 remains, the process returns to the waiting state for the reply message in step 105. However, if they are equal, it is determined that the reply messages for all terminals have been received (step 10).
7).

When it is determined that the reply messages for all terminals have been received, the IP address and MAC address of the duplication analysis terminal 10 are acquired and added to the record of the table 31. Then, the IP addresses in the table 31 are sorted as a key, and records having a plurality of the same IP addresses are extracted (step 108).

The number of records extracted in step 108 is determined. When the number of records having duplicate IP addresses is "0", the message shown in FIG. 5 is displayed. When the number of records is "1" or more, the format shown in FIG. 4 is displayed. Then, the overlapping IP addresses are displayed, and at the same time, the MAC addresses are also displayed in pairs (step 109).

In the example of FIG. 4, the MAC address is "ABC
General terminal 20 of "DEFG" and "70CDXXXXXXX"
It is displayed that the IP address of is duplicated. Since the MAC address is unique to the terminal as described above, it is possible to immediately identify which of the large number of general terminals 20 the IP address is for the user of the specified general terminal 20. You will be notified of the correction of the address.

Therefore, according to this embodiment, it is possible to easily identify the terminals having the duplicate IP addresses and reduce the man-hours spent for this work.

Further, since the IP address reply request is transmitted by the broadcast type message, the burden on the duplication analysis terminal 10 is reduced as compared with the case of individually transmitting the IP address reply request. At the same time, each general terminal can easily distinguish it from a normal communication message.

The IP address duplication analysis process may be carried out at an arbitrary timing determined by the LAN system administrator, such as once a week or once a month.

[0043]

As described above, in the present invention, one terminal in the LAN system is set as an IP address duplication analysis terminal and the others are set as general terminals, and the IP address duplication analysis terminal is set as the general terminal. An IP address reply request is issued to the general terminal from each general terminal
Addresses are returned, a table of the returned IP addresses is created, IP addresses in the table are analyzed, and general terminals with duplicate IP addresses are detected and displayed. It is possible to specify the terminal having the address and reduce the man-hours required for this work.

Therefore, the greater the number of terminals in the LAN system, the more useful it becomes.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an embodiment of a LAN system to which a duplicate IP address detection method of the present invention is applied.

FIG. 2 is a flowchart showing a duplicate IP address detection processing procedure.

FIG. 3 is a table configuration diagram of IP addresses and MAC addresses collected from terminals.

FIG. 4 is an explanatory diagram of display contents indicating that IP addresses are duplicated.

FIG. 5 is an explanatory diagram of display contents indicating that IP addresses are not duplicated.

[Explanation of symbols]

10 ... Duplication analysis terminal, 11 ... Broadcast transmission function, 12 ... Response message reception function, 13 ... Table creation / analysis function, 14 ... Analysis result display function, 15, 23 ...
LAN adapter card, 20 ... General terminal, 21 ... Message receiving function, 22 ... Response message sending function, 31 ...
table.

Claims (1)

[Claims] 1. A method for detecting duplicate IP addresses in a LAN system having a LAN adapter card having a unique MAC address and connecting a plurality of terminals having IP addresses set therein, wherein one terminal in the LAN system has an IP address. The duplication analysis terminal and others are set as general terminals, the IP address duplication analysis terminal issues an IP address reply request to the general terminal, and the general terminal returns the IP address of each general terminal, and the reply A method of detecting a duplicate IP address, characterized in that a table of created IP addresses is created, IP addresses in the table are analyzed, and general terminals with duplicate IP addresses are detected and displayed.