JP2001285349A - System for fixing of arp table and method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix specified address information at an ARP(Address Resolution Protocol) table. SOLUTION: The system for fixing of ARP table includes an ARP table controller receiving a fixing target address and a waiting time of status monitoring for the table so as to set and control the information of the table, and the ARP table controller comprises a fixing target address storage, a present ARP table obtaining means, a fixing address reading part, an address comparing means comparing two addresses obtained from a fixing address reading part and an ARP table reading part, a fixing means fixing the address matched at the comparing means and a waiting means waiting a processing for the time obtained at a waiting time reading means after the processing of the fixing means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a communication system that implements an address resolution protocol and updates ARP table information in a communication network.

[0002]

2. Description of the Related Art Conventionally, a LAN (Local Area Network) configured using Ethernet or the like has been known.
k) and the like, the one most commonly used to specify the destination terminal is IP (Internet Protocol).
l) Address. IP address is a logical address (protocol address) recognized by the network layer
Since the network administrator assigns each computer, it does not correspond to the physical address that the computer has in advance. However, actual communication requires not only an IP address but also a physical address.

When one address of a communication partner is known but the other address is unknown, various address resolution protocols are used as means for acquiring unknown address information.

[0004] ARP (Address Resolution)
ion Protocol: address resolution protocol)
Is a protocol used between hosts on a network to find a unique hardware address corresponding to the protocol address of a communication partner. Then, based on the correspondence between the acquired protocol address and the hardware address, data is transmitted and received without being aware of the hardware of the other party at the time of transmission.

The Internet standardization organization, IET
F (Internet Engineering Ta)
sk Force, Internet Technology Standardization Committee)
In RFC 826, "Ethernet (registered trademark) Address Resolution Pro"
“tocol” stipulates the ARP specification.

[0006] The outline of the address resolution processing by ARP will be briefly described below. When transmitting an IP datagram in an IP network, the originating host first searches the address translation table in the cache memory using the IP address of the communication partner as a key, and determines whether or not the communication partner is registered. If it is checked and registered, the physical address is set as the destination address of the IP datagram. If there is no corresponding registration information, ARP is activated to acquire the physical address of the communication partner. The physical address thus obtained is registered in the address conversion table in combination with the IP message. Therefore, efficient address translation can be performed thereafter by referring to the address translation table.

FIG. 6 is an explanatory diagram showing the concept of address resolution by ARP. In the figure, a host a sets an IP address Py of a known partner in an ARP request message (ARP request) and broadcasts it on the LAN in order to know the physical address of the communication partner. This AR
The host y having received the P request message returns a response message in which the physical address and the IP address are paired to the host a as the inquiry source. Then, the host a registers the set of the physical address and the IP address of the host y in the address conversion table, and thereafter checks the entries in this table to perform address conversion.

Thus, the host a on the LAN is connected to the host y
When transmitting the IP datagram to the
If you know the address but not the physical address,
The physical address of the host y can be obtained using ARP.

[0009] As a prior art using such ARP, there is a network address resolution method and an address resolution terminal described in JP-A-11-27298. In this prior art, every time communication is performed, all hosts on the LAN including the host of the communication partner receive and process the broadcast packet once, and only the host whose logical address matches responds. In response to the problem of an increase in overhead, information including the logical address and the physical address is broadcasted once to each network when each terminal is started, and each address resolution terminal that receives the information addresses the logical address and the physical address contained therein. Since the address and the address are registered in the address table, the overhead after that is reduced.

[0010]

However, the conventional ARP
In the processing, when there is no technique for fixing the address in the ARP table, for example, in a network implementing the UDP / IP protocol, the communication is interrupted during the execution of the communication program and the communication is interrupted for 30 minutes or more. If the address of the communication partner disappears from the ARP table, communication becomes impossible and the program must be restarted.

[0011]

An ARP table fixing system and an ARP table fixing method according to the present invention receive an address to be fixed and a standby time for monitoring the state of the ARP table, and receive information of the ARP table. An ARP table management unit for performing setting management, wherein the ARP table management unit is an address for comparing the two addresses obtained from the fixed address reading unit, the fixed ARP table acquisition unit, the fixed address reading unit, and the ARP table. There are a comparison unit, a fixing unit for fixing an address matched by the address comparison unit, and a standby unit for waiting for processing for a time obtained by the standby time reading unit after the processing by the fixing unit.

Further, the present invention provides an address to be fixed,
An ARP table management unit that receives an address mask value and a standby time for monitoring the state of the ARP table and performs setting management of information of the ARP table, wherein the ARP table management unit includes: Address mask value storage means, current ARP table acquisition means, fixed address reading, address comparison means for masking an address obtained from the ARP table with the address mask value and comparing the masked addresses, There is a fixing means for fixing the coincident address by the means, and a waiting means for waiting for the processing for a time obtained by the waiting time reading means after the processing by the fixing means.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In view of the above problems, the present invention has
It is intended to provide a configuration that can fix an arbitrary address of the RP table. Here, “fixing” refers to a process of always storing specific address information on an ARP table.

In FIG. 1, when the communication terminal 100 having the test processing unit 101 and the device under test 110 are connected via a network, the communication terminal 100 and the device under test 1 are connected.
Reference numeral 10 denotes a UDP / IP (User D) via a test processing unit.
atagram Protocol / Internet
Protocol), and perform data communication. In this case, the protocol address is an IP address, and the physical address is a MAC address. Here, A
An RP table 102 is created, and the IP address and MAC (Media Access Cont
(roll) Holds the address.

However, in the case of UDP / IP, the IP address and the MAC address disappear from the ARP table on the computer in about 30 minutes after the data communication stops. ARP
When the IP address and the MAC address of the communication partner disappear from the table, subsequent communication becomes impossible. Therefore, the present invention manages the ARP table on the communication terminal and prepares a resident program for preventing necessary information from disappearing so that communication is not interrupted.

Referring to FIG. 1, one embodiment of the ARP table fixing system of the present invention is a communication terminal (or central processing unit; processor; data processing unit) 100 operated by program control; When,
ARP table 102 and ARP table management unit 103
, A device under test 110, and a network 120. Here, the test processing unit 101 has a communication processing function of performing transmission / reception processing of communication data by various applications with the device under test 110 which is another communication terminal.

The ARP table management unit 103 is configured as shown in FIG.
The configuration is as shown in FIG. FIG. 2 is a functional block diagram of the ARP table management unit according to the embodiment of the present invention. ARP
The table management unit 103 has an interface for storing information input by a user using an input device and acquiring information of the ARP table 102.

Hereinafter, the configuration of the ARP table management unit 103 will be described. The user uses the input device 104 to input a specific IP address and
Enter the waiting time. Here, the standby time means whether the specified address to be fixed is not erased at regular intervals specified by the standby time with respect to the information in the ARP table which is constantly rewritten according to the communication status. The time interval for monitoring information.

Next, in response to the information input from the input device 104, the fixing target address storage unit 1 stores the input fixing target address. The fixation target address reading unit 4 reads the address stored in the fixation target address storage unit 1.

The current ARP table acquisition section 2 acquires the ARP table 102 in the current state.
Further, the ARP table reading unit 5 reads the ARP table acquired by the current ARP table acquiring unit 2 by one piece of information (one entry). Here, one entry is, specifically, a MAC address registered in the ARP table corresponding to each IP address.

The address comparing section 7 stores the address to be fixed read by the fixed address reading section 4 and the AR
The addresses stored in the current ARP table obtained by the P table reading unit 5 are compared. And the current AR
A search is performed for addresses to be fixed in the P table, and when an address to be fixed is detected, the process is passed to the fixing unit 8. The fixing unit 8 is an address comparing unit 7
The fixation process is performed on the address that matches.

Here, the fixed processing means that information is updated in the ARP table according to the communication state, and when the corresponding communication is interrupted for a certain period of time, each entry information is deleted by the aging processing. However, in software, this is performed by transmitting a command to the OS (operation system) to instruct the entry information to be fixed. In the fixing process, as a specific operation, for example, the entry information is always deleted from the ARP table by storing the address to be fixed in the storage unit and periodically writing information in the ARP table. It can be implemented so as not to be performed.

On the other hand, the standby time storage unit 3 stores the input standby time for the input standby time. The standby time reading unit 6 reads the standby time stored in the standby time storage unit 3. After the processing of the fixing unit 8, the standby unit 9 waits for the processing for the time obtained by the standby time reading unit 6. Needless to say, each of the above-described configurations can be realized either in hardware or by a processing function using software.

Next, the operation of this embodiment will be described with reference to FIG. The address to be fixed, which is a startup parameter, is stored in the address to be fixed address storage unit 1, and the standby time is stored in the standby time storage unit 3 (step 31). next,
The current ARP table acquisition unit 2 acquires the current ARP table (step 32).

The address comparing section 7 obtains the address to be fixed by using the address reading section 4 to be fixed, and obtains one entry of the current ARP table by using the ARP table reading section 5. Then, the obtained addresses are compared. This is repeated while there is table information (step 33). If there is an address to be fixed in the table (step 33: YES),
The fixing is performed by the fixing unit 8 (step 34).

If there is no address to be fixed in the table (step 33: NO), or after step 34, the standby unit 9 waits for processing (step 35). The standby unit 9 acquires the standby time by using the standby time reading unit 6. After waiting in the standby unit 9 for the specified time, the processing is restarted from step 32 and the current ARP table is obtained. This is because the ARP table changes with time.

As described above, in the embodiment of the present invention, by fixing a specific address, even in a system in which the aging process of the ARP table is performed, the communication using the desired address is immediately performed. It can be carried out. Further, by repeatedly searching for the address to be fixed in the table, important address information can be held at the set value even when an IP address is rewritten by another user.

Next, another embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, the specification of the address to be fixed is set by an address mask value. Referring to FIG. 4, in an embodiment of the ARP table fixing system according to the present invention, the fixing target address storage unit 1 stores an input fixing target address. The current ARP table acquisition unit 2 acquires a current ARP table.

The address mask value storage 10 stores the input address mask value. The ARP table reading unit 5 reads the table obtained by the current ARP table obtaining unit 2 one entry at a time. The fixing target address reading unit 4 reads the address stored in the fixing target address storage unit 1. The address comparing unit 7 masks the two addresses obtained by the fixed address reading unit 4 and the ARP table reading unit 5 with the mask value obtained by the address mask value reading unit 11, and compares the masked addresses.

Here, the address indicates an IP address, and this IP address is represented by 32 bits and is usually represented by dots. (For example, 10.10.1
0.10). Here, the address mask value is 255.25.
Assuming 5.255.0, the masked result is 10.1
0.10.0. Therefore, the addresses to be compared are 10.10.10.10 and 10.10.10.11, respectively.
When masked with the address mask value,
0.10.10.0 and 10.10.10.0.0 are obtained, and the comparison results match.

The fixing unit 8 fixes the address matched by the address comparing unit 7. The standby time storage stores the input standby time. The standby time reading unit 6 reads the standby time stored in the standby time storage unit 3. After the processing of the fixing unit 8, the standby unit 9 waits for the processing for the time obtained by the standby time reading unit 6.

By using the address mask value in this manner, there are a plurality of addresses to be fixed, and if the addresses are similar, the addresses can be fixed without inputting a plurality of fixed addresses.

Next, the overall operation of this embodiment will be described in detail with reference to FIGS. As shown in the figure, the fixation target address, which is a startup parameter, is stored in the fixation target address storage unit 1, and the standby time is stored in the standby time storage unit 3 (step 51). Next, the current ARP table acquisition unit 2 acquires the current ARP table (step 52).

The address comparing section 7 acquires the address to be fixed by using the address reading section 4 to be fixed, and acquires one piece of information of the current ARP table by using the ARP table reading section 5. Each of the acquired addresses is masked with the acquired address mask value using the address mask value reading unit 11 (step 53). Next, each masked address is compared. This is repeated while there is table information (step 54).

If there is an address to be fixed in the table, it is fixed by the fixing unit 8 (step 5).
5). If there is no address to be fixed in the table, or after step A4, the standby unit 9
The process waits (step 56).

The standby unit 9 acquires the standby time by using the standby time reading unit 6. After waiting for the processing for the designated time in the standby unit 9, the processing is restarted from step 52. This is because the ARP table changes with time.

As described above, in another embodiment,
The address to be fixed is specified by the subnet mask value, and mainly the IP version. Although the description has been given for the class of four addresses, this specification may be a method of specifying an arbitrary bit string to mask an address group in a specific range, or the specification of IP ver. A mask may be applied to a group of addresses in a specific range according to the six-address system.

[0038]

As described above, the first effect of the present invention is that, in a network using the UDP / IP protocol or the like, an unfixed address in the ARP table is deleted from the table after a certain period of time. It is another object of the present invention to provide a system that performs aging of the ARP table with a means for fixing a designated address in the ARP table.

The second effect is that the ARP table which is constantly updated is repeatedly searched for the address to be fixed in the table, so that even if the address to be fixed does not exist, the address is fixed later. You can search for addresses that will be present. Therefore, even when the ARP table information of the communication terminal is locally rewritten, communication intended by a network administrator or the like can always be normally performed.

[Brief description of the drawings]

FIG. 1 is a system configuration according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of an ARP table management unit according to the embodiment of the present invention.

FIG. 3 is a flowchart showing the operation of the embodiment of the present invention.

FIG. 4 is a functional block diagram of an ARP table management unit according to another embodiment of the present invention.

FIG. 5 is a flowchart showing the operation of another embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a concept of address resolution by ARP.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed address storage part 2 Current ARP table acquisition part 3 Standby time storage part 4 Fixation target address storage part 5 ARP table reading part 6 Waiting time reading part 7 Address comparison part 8 Fixation part 9 Standby part 10 Address mask value Storage unit 11 Address mask value reading unit 100 Communication terminal 101 Test processing unit 102 ARP table 103 ARP table management unit 104 Input device 110 Device under test 120 Network

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K030 HA08 HC14 HD09 JT02 KA05 KA08 LD17 LD18 5K033 CB13 DB12 EC04 9A001 BB03 BB04 CC06 CC08 DD10 FF03

Claims (9)

[Claims] An address resolution protocol for obtaining a physical address from a protocol address of a communication partner on a network, a correspondence between protocol address information of another communication terminal obtained by the address resolution protocol, and physical address information. In a communication terminal having an ARP table that stores information as registration information for a certain period of time, the communication terminal specifies a specific address for the ARP table and performs fixation, and specifies the ARP table for the ARP table. An ARP table fixing system, comprising: means for searching for and fixing the fixed address at a time interval and maintaining communication with the address. 2. An address resolution protocol for acquiring a physical address from a protocol address of a communication partner on a network, correspondence between protocol address information of another communication terminal acquired by the address resolution protocol, and physical address information. In a communication terminal having an ARP table that stores information as registration information for a certain period of time, the communication terminal specifies a specific address mask for the ARP table and performs fixing of an address group. On the other hand, an ARP table fixing system comprising means for searching for and fixing the fixed address group at specified time intervals and maintaining communication with the address. 3. The communication terminal according to claim 1, wherein said communication terminal inputs, from a user, an address to be fixed and a time interval for monitoring a state of an ARP table, and transmits and receives communication data to and from another communication terminal on said network. The ARP table fixing system according to claim 1 or 2, further comprising: a processing unit; and an ARP table management unit that acquires information and manages settings of the ARP table. 4. An address resolution protocol for obtaining a physical address from a protocol address of a communication partner on a network, correspondence between protocol address information of another communication terminal obtained by the address resolution protocol, and physical address information. A communication terminal having an ARP table for storing information as registration information for a fixed time, the communication terminal comprising: an input unit for inputting, from a user, an address to be fixed and a time interval for monitoring the state of the ARP table; A processing unit for transmitting and receiving communication data to and from another communication terminal, and an ARP table management unit for acquiring information and setting management of the ARP table, wherein the ARP table management unit A fixed target address storage means for storing the target address; Current ARP table obtaining means for obtaining an ARP table, ARP table reading means for reading the table obtained by the current ARP table obtaining means, fixing target address reading means for reading the address stored in the fixing target address storing means, ARP table fixing comprising: an address comparing means for comparing two addresses obtained by a fixed address reading means and an ARP table reading means; and a fixing means for fixing an address matched by the address comparing means. system. 5. An ARP table management unit comprising: a standby time storage unit for storing an input standby time; a standby time reading unit for reading a standby time stored in the standby time storage unit; 5. The ARP table fixing system according to claim 4, further comprising a standby unit that waits for processing for a time obtained by the standby time reading unit. 6. An address resolution protocol for acquiring a physical address from a protocol address of a communication partner on a network, correspondence between protocol address information of another communication terminal acquired by the address resolution protocol, and physical address information. A communication terminal having an ARP table for storing information as registration information for a fixed time, the communication terminal comprising: an input unit for inputting, from a user, an address to be fixed and a time interval for monitoring the state of the ARP table; A processing unit that transmits and receives communication data to and from another communication terminal; and an ARP table management unit that performs information acquisition and setting management for the ARP table. Fixed address storage means for storing the address to be fixed, Current ARP table obtaining means for obtaining a current ARP table; address mask value storing means for storing an input address mask value; ARP table reading means for reading a table obtained by the current ARP table obtaining means; A fixed address reading means for reading an address stored in the fixed address storing means; and masking the two addresses obtained by the fixed address reading means and the ARP table reading means with a mask value obtained by the address mask value reading means. 4. The apparatus according to claim 3, further comprising: address comparing means for comparing the masked addresses with each other; and fixing means for fixing an address matched by the address comparing means.
RP table fixing system. 7. An ARP table management unit, comprising: a standby time storage unit for storing the input standby time; a standby time reading unit for reading the standby time stored in the standby time storage unit; 7. The ARP table fixing system according to claim 6, further comprising a standby unit that waits for processing for a time obtained by the standby time reading unit. 8. The ARP table fixing system according to claim 2, wherein the address mask value is specified by an address class or an arbitrary bit. 9. An address resolution protocol (ARP) for obtaining a physical address from a protocol address of a communication partner on a network, protocol address information of another communication terminal obtained by the address resolution protocol, and a physical address. A communication terminal having an ARP table for storing correspondence information of information as registration information for a fixed time, wherein the communication terminal inputs a fixed target address and a time interval for monitoring the state of the ARP table; On the other hand, the step of fixing an address group by designating a specific address mask; and searching and fixing the fixed address group with respect to the ARP table at a specified time interval, Maintaining communication. ARP table immobilization method according to symptoms.