JPH1127298A - Address solution method for network and address solution terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an address solution method and an address solution server for a network that registers a hardware address only of a server and host in an active state and can simply recognize a host server in an inactive state. SOLUTION: At the activation of a host 11, its hardware address 'HA' and a logical address 'LA' are broadcasted to a network; an address solution server 20 which receives them allocates the hardware address 'HA' and the logical address 'LA' of the host 11 for registration in an address table 210; and from the address solution servers 20, its own hardware address 'HS' and the logical address 'LA' are transmitted to the host 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an address for knowing a hardware address of each server and host in a network in which a plurality of computer systems are connected to a communication line such as a LAN line as a server or host. Regarding the solution.

[0002]

2. Description of the Related Art In a network in which a plurality of computer systems are connected to a communication line such as a LAN as a server and a host, a unique hardware address (physical address) is assigned to each server and host in advance. However, a logical address managed by a network protocol is used for actual management. Therefore, for example, when performing communication from a certain host to another certain host, it is necessary for the sending host to specify the hardware address of the communication partner host as the destination, but usually only the logical address is determined. I have. Therefore, when performing communication in a network, it is necessary to resolve the correspondence between the logical address and the hardware address.

Conventionally, a transmitting side has taken the following procedure in order to know a hardware address from a logical address of a communication partner. That is, the transmitting side broadcasts the logical address of the communication partner to the network (broadcast communication).
Then, all the servers and hosts connected to the network receive it, and the host or server with the matching logical address returns the hardware address, so that the sending host can communicate with the hardware of the communication partner host. I was able to know the wear address.

However, in such a conventional method, all the hosts on the LAN including the host of the original communication partner once receive the packet broadcast to the network, and only the host whose logical address coincides responds. Therefore, overhead occurs. This overhead is
Because it occurs every time communication is performed on the network,
Very uneconomical.

In view of such circumstances, for example, Japanese Patent Application Laid-Open
No. 8-263415 (IPC G06F 13/00 355, H04L 12/46, H04
L12 / 28, H04L 12/40) have been proposed. In the invention of Japanese Patent Application Laid-Open No. 8-263415, a server having a database in which a logical address and a hardware address are permanently set in association with each other is provided, and when communicating with another host, the hardware address of the host of the communication partner is To the server.

[0006]

In the conventional method as described above, every time communication is performed, all the hosts on the LAN including the host of the communication partner once receive the broadcast packet and process it. Since only the host whose logical address matches responds, there is a problem that overhead increases.

In the invention disclosed in Japanese Patent Application Laid-Open No. Hei 8-263415, the association between a logical address and a hardware address becomes semi-permanent. For example, when the logical address of a certain host is changed, the hardware becomes When a hardware address is changed due to replacement, special measures are required, and when it is out of service, the host is present but unable to communicate. There is a problem. In other words, there is no guarantee that constant communication is possible with all of the hosts and servers for which hardware addresses are registered.

The present invention has been made in view of such circumstances, and does not require a broadcast for knowing the hardware address of a communication partner, and can easily change the logical addresses and hardware addresses of a host and a server. And the hardware addresses of only the servers and hosts that are in operation are registered.
It is an object of the present invention to provide a network address resolution method and a network address resolution server capable of easily recognizing an inactive host or server.

[0009]

A network address resolution method according to the present invention comprises a plurality of terminals each having a fixedly assigned physical address and an arbitrarily set logical address, and at least one address. A method for resolving a network address for obtaining a physical address corresponding to a logical address of each terminal on a network connected to a resolution terminal, wherein each terminal includes a first logical address and a first physical address including its own logical address at the time of startup. When the address resolution terminal receives the first information, it registers the logical address and the physical address included in the first information in the address table while associating the logical address with the physical address. To the source of the first information, and each terminal sends the When the terminal receives the logical address and the physical address, the terminal stores the logical address and the physical address. At the time of shutdown, each terminal transmits second information including at least one of its own logical address and physical address to the address resolution terminal. When the second information is received, the registered contents of the address table corresponding to the logical address or the physical address included in the second information are deleted, and each terminal communicates with the other terminal before communicating with another terminal. The third information including the logical address is transmitted to the address resolution terminal. When the third information is received, the address resolution terminal changes the physical address registered in the address table corresponding to the logical address included in the third information. The third information is transmitted to a transmission source.

In the network address resolution method of the present invention, when each terminal is started, the first information including the logical address and the physical address is broadcast to the network, and the address resolution terminal that receives the first information broadcasts the first information. The included logical address and physical address are registered in the address table in association with each other.
At this time, the address resolution terminal transmits its own logical address and physical address to the source of the first information. Therefore, the terminal that transmitted the first information determines the logical address and the physical address of the address resolution terminal. You can know. When each terminal is shut down, the second information including at least one of the logical address and the physical address is transmitted to the address resolution terminal, and the address resolution terminal that has received the second information stores the logical address or the physical address included in the second information. The registered contents of the corresponding address table are deleted. Further, when each terminal communicates with another terminal, a third address including the logical address of the communication partner is preceded.
Is transmitted to the address resolution terminal, and the address resolution terminal receiving the information transmits the physical address registered in the address table corresponding to the logical address included in the address resolution terminal to the source of the third information.

The address resolution terminal of the network according to the present invention obtains a physical address corresponding to a logical address of a plurality of terminals each having a fixedly assigned physical address and an arbitrarily set logical address. An address table for registering a physical address and a logical address, means for receiving first information including a logical address and a physical address from the network, and receiving the first information Means for associating a logical address and a physical address included in the address information with each other and registering them in an address table; and, when receiving the first information, sets its own logical address and physical address to the source of the first information. Means for sending to the network as a destination, and logical or physical address with predetermined information Means for receiving second information including at least one from the network, means for deleting the registered contents of the address table corresponding to the logical address or the physical address included in the second information when the second information is received, Means for receiving, from the network, third information that includes an address but does not include a physical address; and, when the third information is received, a physical address registered in an address table corresponding to a logical address included in the third information. Means for transmitting the information to the network with the transmission source of the information as the destination.

In the network address resolution terminal of the present invention, each terminal receives the first information including the logical address and the physical address transmitted at the time of startup, and determines the logical address and the physical address included in the first information. Register it in the address table in association with it. Also, at this time, each terminal is notified by transmitting its own logical address and physical address to the network with the source of the first information as the destination. Further, each terminal receives the second information including at least one of the logical address and the physical address transmitted together with the predetermined information at the time of shutdown, and registers the content of the address table corresponding to the logical address or the physical address included therein. To kill. Still further, each terminal receives third information including the logical address of the communication partner transmitted prior to communication with the other terminal but not including the physical address, and stores the third information in the address table corresponding to the logical address included therein. By transmitting the registered physical address to the network with the source of the third information as the destination, the terminal of the source of the third information is notified.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments. FIG. 1 is a schematic diagram showing a configuration example of a network including an address resolution server as an address resolution terminal of the present invention, for implementing a network address resolution method of the present invention.

This network uses L as a communication line.
Various terminals, that is, a plurality of hosts 11, 12,... And a plurality of servers 20 are connected to the AN line 1. However, in the example shown in FIG. 1, as a minimum configuration for implementing the network address resolution method of the present invention, the hosts 11 and 12 as two terminals and the address as one address resolution terminal are used. Although a resolution server 20 is shown, more hosts and various servers are actually connected to the LAN line 1.

The hosts 11 and 12 are basically ordinary computer systems, both of which have CPUs 110 and 120 and a ROM 11
1, 121, and hard disk drives (HDD) 112, 122,
At least interfaces (I / O) 113 and 123 with the LAN line 1 are provided. CPUs 110 and 120 are connected to hosts 11 and 12, respectively.
Controls internal control and communication with the network. ROM
111 and 121 store software programs for controlling the respective hosts 11 and 12, and also store hardware addresses (physical addresses). HDD 112, 1
22 stores various data necessary for the respective hosts 11 and 12, but also stores respective logical addresses.

The hardware connected to the LAN line 1 is assigned a physical address in advance and the ROM 111,
The hardware address of the host 11 is assigned to “HA” and that of the host 12 is assigned to “HB”. The logical address connected to the LAN line 1 can be arbitrarily set as long as the logical address does not overlap with other logical addresses and is stored in the HDDs 112 and 122.
It is assumed that “LA” is set as the logical address of 11 and “LB” is set as the logical address of the host 12.

As described above, since the logical address can be arbitrarily set, it can be changed at any time. However, since the hardware address is fixedly assigned to each piece of hardware, the hardware itself can be used. When the hardware address is replaced, the hardware address is naturally changed. However, also in this case, it is possible to replace hardware without changing the logical address.

The address resolution server 20 of the present invention is also basically a normal computer system, and includes a CPU 200, an RO
Interface between M 201, HDD 202 and LAN line 1
(I / O) 203 at a minimum. The CPU 200 controls the inside of the address resolution server 20 and the communication with the network, and also manages the address table 210. ROM
201 stores a software program for controlling the address resolution server 20 (including a software program for managing the address table 210) and also stores a hardware address. The HDD 202 stores various data necessary for the address resolution server 20, stores the address table 210 therein as described above, and further stores the logical address of the address resolution server 20.

Note that the address resolution server 20 is assigned "HS" as a hardware address,
It is assumed that the logical address is set to “LS” and stored in the HDD 202.

As apparent from the above description, the difference between the address resolution server 20 and the other hosts 11, 12,... Is that it has an address table 210. In the example shown in FIG. 1, the address table 210
Although it is set in an appropriate area in 202, any storage means whose contents can be rewritten, such as a hard disk or a flash memory, can be used. In the address table 210, logical addresses and hardware addresses of other hosts and servers including the hosts 11 and 12 connected to the LAN line 1 to which the address resolution server 20 is connected are set as needed. Registered and deleted.

The network address solving method of the present invention implemented in a network having such a configuration will be described with reference to the flowcharts shown in FIG.

First, the operation of registering a logical address and a hardware address in the address resolution server 20 when each host or server starts up will be described with reference to the flowchart of FIG. In the following description, the host
The operation when 11 is started is taken as an example.

When the host 11 is started, the CPU 110 first reads its own logical address "LA" from the HDD 112 and reads the hardware address "HA" from the RAM 111, and reads packets of a specific format containing these contents. (Hereinafter referred to as an address registration packet) is broadcast to the LAN line 1 as shown by a reference numeral P1 in FIG. 1 (step S11). The address registration packet P1 broadcast from the host 11 is received by all hosts and servers connected to the LAN line 1 including the address resolution server 20. However, this address registration packet
P1 is processed only by the address resolution server 20, and other hosts and servers ignore it even if it receives it.

When the address resolution server 20 receives the address registration packet P1 broadcast from the host 11, the CPU 200 analyzes the contents and obtains the logical address "LA" and the hardware address "HA" of the host 11. And register it in one entry of the address table 210 (step S12).

Next, the CPU 200 of the address resolution server 20
Its own logical address "LS" is read from the HDD 202, and the hardware address "HS" is read from the ROM 201, and a packet of a specific format (hereinafter, referred to as an address registration response packet) containing these contents is described as a hardware address " The transmission is performed with “HA” as the destination, in other words, with the host 11 as the destination, as indicated by reference numeral P2 in FIG. 1 (step S13).

The destination of the address registration response packet P2 transmitted from the address resolution server 20 is specified to the hardware address “HA” (specifically, the host 11). Is received only by the host 11 having

When the host 11 receives the address registration response packet P2 transmitted from the address resolution server 20 to its own hardware address “HA”, the CPU 11
0 is the logical address “L” indicating the source by analyzing the contents
S ”and the hardware address“ HS ”are obtained and stored in the HDD 112 as the logical address and the hardware address of the address resolution server 20 (step S14).

As described above, the broadcast of the address registration packet P1 from the host 11 and the transmission of the address registration response packet P2 from the address resolution server 20 to the host 11 in response thereto are performed. In one entry of the address table 210, the hardware address "HA" of the host 11 and the logical address "LA" are registered in association with each other.
The HDD 112 stores the hardware address “HS” and the logical address “LS” of the address resolution server 20. In this way, the address table 21 of the address resolution server 20
Since the hardware address “HA” and the logical address “LA” of the host 11 are registered in “0”, the address resolution server 20 can recognize that the host 11 has already been started and is operating.

In the above-described example, the processing at the time of starting the host 11 has been described. However, in any host or server including the other host 12, the respective logical addresses and hardware addresses are similarly processed by the address resolution server. Needless to say, it is possible to register for 20.

Next, the operation of deleting a logical address and a hardware address from the address resolution server 20 when each host or server shuts down will be described with reference to the flowchart of FIG. In the following description, a case where the host 11 is shut down is taken as an example.

When the host 11 shuts down, the CP
The U 110 transmits a packet of a specific format (hereinafter, an address deletion request packet) to the hardware address “HS” of the address resolution server 20 as indicated by reference numeral P3 in FIG. 1 (step S21). .

When the address resolution server 20 receives the address deletion request packet P3, the CPU 200 deletes the hardware address "HA" and the logical address "LA" of the host 11 registered in the address table 210 from the entry. (Step S22).

As described above, since the hardware address "HA" and the logical address "LA" of the host 11 are deleted from the address table 210 of the address resolution server 20, the CPU 20 of the address resolution server 20 searches the address table 210. In this case, it is possible to recognize that the host 11 is not operating.

Next, an operation when communication is performed from a certain host to another certain host will be described with reference to a flowchart of FIG. In the following description, an operation when communication is performed from the host 11 to the host 12 will be described as an example.

When the host 11 communicates with the host 12,
That is, when the host 11 is the sending host and the host 12 is the receiving host, the CPU 110 of the host 11 first
Packet of a specific format containing the logical address "LB" of the address (hereinafter referred to as an address resolution request packet)
LAN address 1 with hardware address "HS" as destination
Is transmitted as indicated by reference numeral P4 in FIG.
(Step S31). The address resolution request packet P4 addressed to the hardware address “HS” transmitted from the host 11 is received only by the address resolution server 20.

When the address resolution server 20 receives the address resolution request packet P4 transmitted from the host 11,
200 analyzes the contents and finds the logical address “L” of host 12.
To obtain "B", it is checked whether or not there is an entry corresponding to the logical address "LB" in the address table 210 (step S32). If there is no corresponding entry ("NO" in step S33), Like that logical address "
CPU 200 indicates that the host having logical address “LB” (in this case, host 12) is inactive because the host having LB ”(in this case, host 12) is inactive. An address resolution response packet P5 of a specific format having data meaning that the hardware address "HA" is transmitted to the LAN line 1 as indicated by reference numeral P5 in FIG.
S34). This address resolution response packet is received only by the host 11.

The host having the logical address "LB"
When the host 11 receives the address resolution response packet P5, which means that (the host 12 in this case) is inactive,
CPU 110 ends the process without performing communication.

On the other hand, when there is an entry corresponding to the logical address "LB" in the address table 210 (step S33)
"YES"), the CPU 200 of the address resolution server 20 reads the hardware address "HB" registered in association with the logical address "LB" from the address table 210, and reads both addresses "LB", "". The host 11 sends an address resolution response packet of a specific format containing "HB"
LAN address 1 with hardware address "HA"
Is transmitted as indicated by reference numeral P6 in FIG.
(Step S35). This address resolution response packet P6 is received only by the host 11.

The address resolution response packet P6 is sent to the host
When the data is received by the CPU 11, the CPU 110 analyzes the contents and obtains the hardware address "HB" corresponding to the logical address "LB" (step S36). As a result, the CPU 110 of the host 11
Generates an original communication packet addressed to the hardware address “HB” and sends it to the LAN line 1 in FIG.
Send as indicated by. From the above, the host
Communication is performed from 11 to the host 12 (step S38)
"YES").

If the communication from the host 11 to the host 12 is unsuccessful ("NO" in step S38)
For example, it is conceivable that the host 12 enters the non-operation state without performing the shutdown processing shown in the flowchart of FIG. 2 (for example, the power is suddenly cut off due to an accident, a power failure, or the like). In this case, although details are omitted, for example, the host 11 transmits a packet to the address resolution server 20 indicating that the communication with the host 12 has been unsuccessful. It is conceivable to perform processing such as deleting the registration of the 12 addresses “LB” and “HB”.

[0041]

As described in detail above, according to the network address resolution method of the present invention, when each terminal is started, the first information including the logical address and the physical address is broadcast to the network, and Received from the address resolution terminal, the logical address and the physical address contained therein are associated with each other and registered in the address table. For this reason, since each terminal only needs to broadcast once at the time of startup, overhead is reduced.

In the above case, since the address resolution terminal transmits its own logical address and physical address to the source of the first information, the terminal that transmitted the first information is the logical address of the address resolution terminal. It is not necessary to check or register the logical address and the physical address of the address resolution terminal in advance because the address and the physical address can be known.

When each terminal shuts down, second information including at least one of the logical address and the physical address is transmitted to the address resolution terminal, and the address resolution terminal receiving the second information transmits the logical address or the logical address included in the second information. The registered contents of the address table corresponding to the physical address are deleted. Therefore, when each terminal is shut down, that is, in a non-operating state, it can be easily found out that the terminal is not registered in the address table.

Further, when each terminal communicates with another terminal, third information including the logical address of the communication partner is transmitted to the address resolution terminal prior to the communication, and the address resolution terminal receiving the third information transmits the logical address included in the third information. And transmits the physical address registered in the address table to the transmission source of the third information. For this reason, when each terminal communicates with another terminal, it becomes possible to know the physical address of the communication partner without broadcasting, thereby reducing overhead.

Further, according to the network address resolution terminal of the present invention, each terminal receives the first information including the logical address and the physical address transmitted at the time of activation, and determines the logical address and the physical address included in the first information. Register it in the address table in association with it. At this time, each terminal is notified by transmitting its own logical address and physical address to the source of the first information. For this reason, each terminal only broadcasts once at startup,
Since the logical address and the physical address of the address resolution terminal can be known, the overhead is reduced.

Further, each terminal receives the second information including at least one of the logical address and the physical address transmitted at the time of shutdown, and registers the registered contents of the address table corresponding to the logical address or the physical address included therein. Delete. Therefore, when each terminal is shut down, that is, in a non-operating state, it can be easily found out that the terminal is not registered in the address table.

Further, each terminal receives third information including a logical address of a communication partner transmitted prior to communication with another terminal and is registered in an address table corresponding to the logical address included therein. The transmitted physical address is transmitted to the transmission source of the third information. For this reason, when each terminal communicates with another terminal, it becomes possible to know the physical address of the communication partner without broadcasting, thereby reducing overhead.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration example of a network for implementing a network address resolution method of the present invention.

FIG. 2 is a flowchart of an operation of registering a logical address and a hardware address in an address resolution server when each host or server starts up.

FIG. 3 is a flowchart of an operation for deleting a logical address and a hardware address from an address resolution server when an individual host or server shuts down.

FIG. 4 is a flowchart of an operation when an individual host or server performs communication by obtaining a hardware address of another host or server from an address resolution server.

[Explanation of symbols]

 1 LAN line 11 Host 12 Host 20 Address resolution server 210 Address table P1, P2 ... Packet LA, LB, LS Logical address HA, HB, HS Hardware address

Claims (2)

[Claims] 1. A logical address of each terminal on a network to which a plurality of terminals each having a fixedly assigned physical address and an arbitrarily set logical address and at least one address resolution terminal are connected. A method for resolving a network address for obtaining a physical address corresponding to the following, wherein each terminal broadcasts first information including its own logical address and physical address to the network at the time of startup, When the first information is received, the logical address and the physical address included in the first information are associated with each other and registered in the address table, and the own logical address and the physical address are transmitted to the transmission source of the first information. Each terminal receives the logical address and the physical address from the address resolution terminal. In the case of shutdown, each terminal transmits second information including at least one of its own logical address and physical address to the address resolution terminal at the time of shutdown, and the address resolution terminal transmits the second information. Received from the terminal, the registered contents of the address table corresponding to the logical address or the physical address included in the received terminal are deleted. 3 to the address resolution terminal, and when the address resolution terminal receives the third information, the address resolution terminal registers the physical address registered in the address table corresponding to the logical address included in the third information. Third
A method for resolving a network address, comprising transmitting the information to a source. 2. A network address resolution terminal for obtaining physical addresses corresponding to logical addresses of a plurality of terminals each having a fixedly assigned physical address and an arbitrarily set logical address, An address table for registering a physical address and a logical address; a unit for receiving first information including a logical address and a physical address from the network; and a logical address included in the first information when the first information is received. Means for registering a physical address in association with the address table and, when receiving the first information, a logical address and a physical address of the own device to the network with a source of the first information as a destination Means for transmitting, and at least one of a logical address and a physical address together with predetermined information Means for receiving the second information from the network; means for deleting the registered contents of the address table corresponding to the logical address or the physical address included in the second information when the second information is received; Means for receiving, from the network, third information that does not include a physical address, and a physical address registered in the address table corresponding to a logical address included in the third information when the third information is received. Means for transmitting the third information to the network with the transmission source of the third information as a destination.