JP3507760B2 - ARP table fixing system and ARP table fixing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention 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.
In k), etc., IP (Internet Protocol) is most commonly used to specify a destination terminal.
l) An address. IP address is a logical address (protocol address) recognized at the network layer
Since it is assigned to each computer by the network administrator, it does not correspond to the physical address that the computer has in advance. However, in actual communication, not only the IP address but also the physical address is required.

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.

ARP (Address Resolution)
Ion Protocol: Address resolution protocol)
Is a protocol that is used between hosts on a network to know a unique hardware address corresponding to the protocol address of a communication partner. Then, based on the acquired correspondence between the protocol address and the hardware address, the data is transmitted / received without being aware of the hardware of the partner at the time of transmission.

IET, a standardization organization for the Internet
F (Internet Engineering Ta)
(sk Force, Internet Technology Standardization Committee)
In RFC 826, “Ethernet (registered trademark) Address Resolution Pro”
“Tocol” specifies the ARP specifications.

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 conversion table in the cache memory using the IP address of the communication partner as a key to check whether the communication partner is registered. If it is checked and registered, its 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, thereafter, efficient address conversion can be performed by referring to the address conversion table.

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

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

As a conventional technique using such an ARP, there is a network address resolution method and an address resolution terminal described in Japanese Patent Laid-Open No. 11-27298. In this conventional technique, every time communication is performed, all hosts on the LAN, including the host of the communication partner, receive and process the broadcast packet, and only the host having the matching logical address responds. To address the problem of increased overhead, each address resolution terminal that broadcasts information containing a logical address and a physical address once upon startup of each terminal and receives the logical address and the physical address Since the address and the address are associated with each other and registered in the address table, the subsequent overhead is reduced.

[0010]

However, the conventional ARP
In the processing, if there is no technique for fixing the address in the ARP table, for example, in a network implementing the UDP / IP protocol, in the state where the communication is interrupted during the execution of the communication program and the communication is interrupted for 30 minutes or more. , When the address of the communication partner disappears from the ARP table, communication cannot be performed and the program needs to 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 waiting time for monitoring the state of the ARP table, and receive the information of the ARP table. An ARP table management unit that performs setting management, and the ARP table management unit is an address for comparing the two addresses obtained from the fixed target address storage unit, the current ARP table acquisition unit, the fixed address read, and the ARP table. The comparison means, the fixing means for fixing the matched address by the address comparison means, and the waiting means for waiting the processing for the time obtained by the waiting time reading means after the processing by the fixing means.

According to the present invention, a fixed target address and
An ARP table management unit that receives the address mask value and the waiting time for monitoring the state of the ARP table and manages the setting of the information of the ARP table is included, and the ARP table management unit includes a fixing target address storage unit, Address mask value storage means, current ARP table acquisition means, fixed address reading means, address comparison means for masking the address obtained from the ARP table with the address mask value, and comparing the masked addresses, and address comparison It has a fixing means for fixing the coincident address by the means and a waiting means for waiting the processing for the time obtained by the waiting time reading means after the processing of the fixing means.

[0013]

The present invention has been made in view of the above problems.
It is intended to provide a configuration capable of fixing an arbitrary address in the RP table. Here, fixing means a process of always storing specific address information in the ARP table.

In FIG. 1, the communication terminal 100 and the device under test 1 are connected in a state where the communication terminal 100 including the test processing unit 101 and the device under test 110 are connected via a network.
10 is a UDP / IP (User D
atagram Protocol / Internet
Data communication is performed in (Protocol). In this case, the protocol address is the IP address and the physical address is the MAC address. Here, in the communication terminal, A
The RP table 102 is created, and the IP address and MAC (Media Access Cont) of the device under test 110 are created.
hold) address.

However, in the case of UDP / IP, the IP address and the MAC address disappear from the ARP table on the computer about 30 minutes after the data communication is interrupted. ARP
When the IP address and 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 that prevents necessary information from being deleted so that communication is not interrupted.

Referring to FIG. 1, an embodiment of an ARP table fixing system of the present invention is a communication terminal (or central processing unit; processor; data processing unit) 100 operating under program control and a test processing unit 101. When,
ARP table 102 and ARP table management unit 103
And 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 and the device under test 110 which is another communication terminal.

Further, the ARP table management unit 103 is shown in FIG.
The configuration is shown in. FIG. 2 is a functional block diagram of the ARP table management unit according to the embodiment of this invention. ARP
The table management unit 103 has an interface that stores information input by a user using an input device and acquires information of the ARP table 102.

The structure of the ARP table management unit 103 will be described below. The user inputs a specific IP address from the input device 104 as an address to be fixed.
Enter the waiting time. Here, the waiting time refers to the information in the ARP table that is constantly rewritten depending on the communication status, and whether the specified fixed target address is not erased at regular intervals specified by the waiting time, or whether the current ARP table is deleted. A time interval for monitoring information.

Next, upon receiving the information input from the input device 104, the fixing target address storage unit 1 stores the input fixing target address. The fixed target address reading unit 4 reads the address stored in the fixed target address storage unit 1.

The current ARP table acquisition unit 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 acquisition unit 2 for each piece of information (1 entry). Here, one entry is specifically a MAC address registered in the ARP table corresponding to each IP address.

The address comparison unit 7 and the fixed address read by the fixed address reading unit 4 and AR
The addresses stored in the current ARP table obtained by the P table reading unit 5 are compared. And the current AR
The P table is searched for an address to be fixed, and when an address to be fixed is detected, the process is passed to the fixing unit 8. The fixing unit 8 is the address comparing unit 7.
Fixing processing is performed on the addresses that match in.

Here, in the fixing process, in the ARP table, the information is updated depending on the communication state, and when the corresponding communication is interrupted for a certain period of time, each entry information is deleted by the aging process. However, in terms of software, this is done by sending a command to the OS (operation system) to instruct the entry information to be fixed. As the specific operation of this fixing process, for example, the fixed target address is stored in the storage unit, and information is periodically written in the ARP table, so that the entry information is always erased from the ARP table. It can be implemented so as not to be performed.

On the other hand, with respect to the input standby time, the standby time storage unit 3 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 process of the immobilization unit 8, the standby unit 9 waits for the process for the time obtained by the standby time reading unit 6. It goes without saying that each of the above-described configurations can be realized by hardware as well as by a processing function using software.

Next, the operation of this embodiment will be described with reference to FIG. The fixed target address, which is a startup parameter, is stored in the fixed target 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 unit 7 uses the fixing target address reading unit 4 to acquire the fixing target address, and uses the ARP table reading unit 5 to acquire one entry of the current ARP table. Then, the respective acquired 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),
Immobilization is performed by the immobilization unit 8 (step 34).

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

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

Other Embodiments of the Invention Next, other embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, the designation of the fixation target address is set by an address mask value. Referring to FIG. 4, in an exemplary embodiment of the ARP table fixing system of the present invention, the fixing target address storage unit 1 stores the input fixing target address. The current ARP table acquisition unit 2 acquires the current ARP table.

The address mask value storage unit 10 stores the input address mask value. The ARP table reading unit 5 reads the table acquired by the current ARP table acquisition unit 2 entry by entry. The fixed target address reading unit 4 reads the address stored in the fixed target address storage unit 1. The address comparison 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 refers to 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 set to 255.25
With 5.255.0, the masked result is 10.1.
It becomes 0.10.0. Therefore, the addresses to be compared are 10.10.10.10 and 10.10.10.11, respectively.
, Then 1 is masked by the address mask value.
The results are 0.10.10.0 and 10.10.10.0, and the comparison results are in agreement.

The fixing unit 8 fixes the addresses matched by the address comparing unit 7. The standby time storage unit 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 process of the immobilization unit 8, the standby unit 9 waits for the process for the time obtained by the standby time reading unit 6.

By using the address mask value as described above, there are a plurality of addresses to be fixed, and if the addresses are similar to each other, the fixed 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 fixed target address which is a start-up parameter is stored in the fixed 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 unit 7 uses the fixing target address reading unit 4 to acquire the fixing target address, and also uses the ARP table reading unit 5 to acquire 1 information of the current ARP table. Each acquired address is masked with the address mask value acquired 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, the fixing unit 8 fixes it (step 5).
5). If there is no fixed address in the table, or after step A4, the standby unit 9
The process waits (step 56).

The standby unit 9 uses the standby time reading unit 6 to acquire the standby time. After waiting the process for the designated time in the standby unit 9, the process is restarted from step 52. This is because the ARP table changes with time.

As described above, in another embodiment,
The fixed target address is specified by the subnet mask value, and the IP ver. Although the description has been made in correspondence with the class of 4 addresses, this specification may be to specify an arbitrary bit string to mask an address group in a specific range, or to specify an IP ver. It may be adapted to a 6-address system to mask a group of addresses in a specific range.

[0038]

As described above, the first effect of the present invention is that, in a network using the UDP / IP protocol or the like, unfixed addresses in the ARP table are deleted from the table after a certain amount of time has passed. Therefore, it is possible to provide a system capable of fixing a specified address in the ARP table to a system that is aging the ARP table.

The second effect is that the ARP table that is constantly updated is searched for the fixed target address in the repeated table, and even if the fixed target address does not exist as a result of the search once, the fixed target address does not exist later. You can search for an address that will exist. Therefore, even when the ARP table information of the communication terminal is locally rewritten, the communication intended by the network administrator or the like can always be normally performed.

[Brief description of drawings]

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

FIG. 2 is a functional block diagram of an ARP table management unit according to the embodiment of this 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 the concept of address resolution by ARP.

[Explanation of symbols]

1 Fixed target address storage 2 Current ARP table acquisition section 3 Standby time storage 4 Fixed target address storage 5 ARP table reading section 6 Standby time reading section 7 Address comparison unit 8 immobilization section 9 Standby 10 Address mask value storage 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 Machine under test 120 networks

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-70299 (JP, A) JP-A-8-263415 (JP, A) JP-A-11-27298 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H04L 12/56 H04L 12/28 200

Claims (9)

(57) [Claims] 1. Correspondence between a physical address information and an address resolution protocol for acquiring a physical address from a protocol address of a communication partner on the network, and protocol address information of another communication terminal acquired by the address resolution protocol. 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 in the ARP table and fixes the information, and specifies in the ARP table. An ARP table fixing system comprising means for performing a search and a fixing process of the fixed address at time intervals and maintaining communication for the address. 2. Correspondence between a physical address information and an address resolution protocol for acquiring a physical address from a protocol address of a communication partner on the network, and protocol address information of another communication terminal acquired by the address resolution protocol. 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 to fix an address group, and the ARP table On the other hand, the ARP table fixing system characterized by having a means for performing a search and a fixing process of the fixed address group at a designated time interval and maintaining communication for the address. 3. The communication terminal transmits / receives communication data to / from another user on the network, input means for inputting a fixed target address and a time interval for monitoring the status of the ARP table from a user. 3. The ARP table fixing system according to claim 1, further comprising a processing unit and an ARP table management unit that acquires and manages information about the ARP table. 4. Correspondence between the physical address information and the address resolution protocol for acquiring the physical address from the protocol address of the communication partner on the network, and the protocol address information of another communication terminal acquired by the address resolution protocol. In a communication terminal having an ARP table that stores information as registration information for a certain period of time, the communication terminal includes an input unit for inputting a fixed target address and a time interval for monitoring the status of the ARP table from a user, Other communication terminals, and a processing unit for transmitting and receiving communication data, and an ARP table management unit for acquiring information and managing settings of the ARP table, and the ARP table management unit receives the fixed input data. The fixed target address storage means for storing the target address, and the current A current ARP table acquisition unit for acquiring an ARP table; an ARP table reading unit for reading the table acquired by the current ARP table acquisition unit; and a fixation target address reading unit for reading the address stored by the fixation target address storage unit, ARP table fixing, comprising fixed address reading means and address comparing means for comparing two addresses obtained by the ARP table reading means, and fixing means for fixing the matched addresses by the address comparing means. system. 5. The ARP table management unit, a standby time storage means for storing the input standby time, a standby time reading means for reading the standby time stored by the standby time storage means, and processing of the fixing means. 5. The ARP table immobilization system according to claim 4, further comprising a standby unit that waits for processing for the time obtained by the standby time reading unit. 6. Correspondence between a physical address information and an address resolution protocol for acquiring a physical address from a protocol address of a communication partner on the network, and protocol address information of another communication terminal acquired by the address resolution protocol. In a communication terminal having an ARP table that stores information as registration information for a certain period of time, the communication terminal includes an input unit for inputting a fixed target address and a time interval for monitoring the status of the ARP table from a user, It further includes a processing unit that transmits and receives communication data to and from another communication terminal, and an ARP table management unit that acquires and sets and manages information about the ARP table, and the ARP table management unit receives the input fixed data. Fixed target address storage means for storing the target address for conversion, A current ARP table acquisition means for acquiring the current ARP table; an address mask value storage means for storing the input address mask value; an ARP table reading means for reading the table acquired by the current ARP table acquisition means; The fixed target address reading means for reading the address stored in the fixed address reading means, and the two addresses obtained by the fixed address reading means and the ARP table reading means are masked by the mask value obtained by the address mask value reading means. The address comparison means for comparing the masked addresses with each other, and the fixing means for fixing the matched addresses by the address comparison means.
RP table fixing system. 7. The ARP table management unit includes a standby time storage means for storing the input standby time, a standby time reading means for reading the standby time stored by the standby time storage means, and a processing after the fixing means. The ARP table fixing system according to claim 6, further comprising: a standby unit that waits for processing for the time obtained by the standby time reading unit. 8. The ARP table fixing system according to claim 2, wherein the address mask value is designated 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 the network, protocol address information of another communication terminal obtained by the address resolution protocol, and a physical address. In a communication terminal having an ARP table that stores corresponding information of information as registration information for a certain period of time, the communication terminal inputs a fixation target address and a time interval for performing status monitoring of the ARP table; On the other hand, a step of fixing an address group by designating a specific address mask, a step of searching and fixing the fixed address group in the ARP table at a specified time interval, and Maintaining communication ARP table immobilization method according to symptoms.