JPH09200260A - Packet regulation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a device capable of securing the normal communication operation of a network equipment handling different types of packets by providing the device with an input means, an frame type regulating means, a protocol type regulating means, and an output means. SOLUTION: The specification of respective frame types and protocol types described in an allowance type specification table 5 is set up to 'allowed' or 'regulated' in accordance with a type to be handled by the network equipment 2Q by operating a specification changing means 6. When a packet Pr is inputted from a transmission line N to the input means 1, the packet Pr is sent to the frame type regulating means 2. The means 2 extracts frame type information from the packet Pr received from the means 1 and compares the extracted information with the contents of a frame type information table to specify the frame type of the packet Pr. Then the means 2 refers to the table 5 and judges whether the packet of the specified frame type can be passed or not.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet control device, and more particularly to a packet control device for selecting only packets having a specific frame type and protocol type from packets transmitted through a network transmission line and inputting them to a network device. Regarding

[0002]

2. Description of the Related Art Communication between computer equipments via a network transmission line consists mainly of transmission and reception of data packets. There are various formats of this data packet, but as shown in FIG. 2A, for example, it is general that a header 60 including predetermined frame type information 60f and a frame 50 of a certain specific format are provided. Further, in the frame 50, as shown in FIG. 2B, a packet destination address 51 and a packet source address 52, a protocol type 53 indicating a packet communication procedure, predetermined communication data 54, and the like are included. include.

A frame type and a protocol type which can be effectively handled are predetermined for each network device connected to the network transmission path. Regarding what kind of frame type and protocol type each network device exchanges packets with depends largely on the network software running on each device, but at least between the devices transmitting and receiving the packet described above. It is necessary that the frame type and the protocol type of are the same.

Conventionally, it has been premised that the frame type and protocol type of a packet transmitted through a single network transmission line are unified into one type among network devices, and such an example has been proposed. It was common. On the other hand, in recent years, the network environment tends to be expanded through gateways and bridges,
The frame types and protocol types of packets that flow through a single network transmission line are also diversifying.

[0005]

However, in the above-mentioned conventional example, when the network device receives a packet of a frame type that the network device cannot support, there is a disadvantage that the interface with the network transmission line does not operate normally. In addition, even if the packet has a compatible frame type, the protocol type may be different, and even when such a packet is received, there is an inconvenience in that the interface operates abnormally as described above.

[0006]

It is an object of the present invention to improve the inconvenience of the conventional example, and particularly in a network that handles a wide variety of packets having different frame types and protocol types, packet regulation that can ensure normal communication operation of network equipment. The purpose is to provide a device.

[0007]

According to a first aspect of the present invention, only an input means for fetching a packet from a network transmission line and only a packet having a permitted frame type among the packets sent from the input means are passed. Frame type restricting means, a protocol type restricting means for allowing only a packet having a protocol type permitted in advance among the packets passing through the frame type restricting means, and a packet passing through the protocol type restricting means for a network device. The output means for outputting is provided.

According to the present invention, only packets having the permitted frame type and protocol type are transmitted from the network transmission line to the upper network device.

According to a second aspect of the present invention, in the packet control device according to the first aspect, a plurality of types of frame types and protocol types are described, and passage of the frame type control means or the protocol type control means should be permitted. An allowable type designation table in which designations of frame type and protocol type are described is provided. The frame type regulation means and the protocol type regulation means have a function of permitting passage of a packet having a frame type or a protocol type designated in the permitted type designation table.

In the present invention, in the frame type regulation means and the protocol type regulation means, it is judged whether or not the packet sent from the input means is to be passed based on the designation described in the allowable type designation table.

According to the third aspect of the present invention, in the packet restriction device according to the second aspect, there is provided a specification changing means for changing the specification of the frame type and the protocol type which are allowed to pass through, which is described in the allowable type specification table. It is equipped with the structure.

In the present invention, the frame type and the protocol type which should be permitted to pass through the frame type regulation unit or the protocol type regulation unit within the range of the frame type and the protocol type described in the permitted type designation table by the designation change unit. Is set appropriately.

The above aims to achieve the above-mentioned object.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG.
It will be described with reference to FIG.

The packet restriction device 10 shown in FIG. 1 uses the network transmission line N to receive a packet P (received packet Pr).
Of the packet Pr sent from the input means 1, a frame type regulation means 2 for passing only a packet having a frame type permitted in advance out of the packets Pr sent from the input means 1, and a packet Pr passed through the frame type regulation means 2. Protocol type restriction means 3 that allows only packets having a protocol type permitted in advance to pass therethrough
And output means 4 for outputting the packet Pr that has passed through the protocol type restriction means 3 to the network device 20.

Further, in this embodiment, as shown in FIG. 2, the packet restriction device 10 includes a plurality of frame types and protocol type types 5c, and a frame type restriction means 2 or a protocol type restriction means 3. Allowable type specification table 5 in which specification 5b of frame type and protocol type that should be allowed to pass is described
It has. Then, the frame type regulation unit 2 and the protocol type regulation unit 3 permit passage of a packet having a frame type or protocol type designated in the permitted type designation table 5.

Further, the packet regulation device 10 is provided with a designation changing means 6 for changing the designation 5b of the frame type and the protocol type which are permitted to pass, which is described in the permission type designation table 5.

More specifically, in the present embodiment, the input means 1 includes the network interface 1a (network I / F) connected to the network transmission line N.
1a) and a transceiver 1b having a transmission / reception function.

The frame type regulation means 2 and the protocol type regulation means 3 are provided with a microcomputer. The frame type restriction unit 2 executes a process of extracting frame type information from a packet, a process of determining the type of the frame type from the extracted frame type information, and the like. Also, the protocol type regulation means 3
A process of extracting protocol type information from the frame and a process of determining the type of the protocol type from the extracted protocol type information are executed. Here, a list of frame type information for discriminating the frame type is stored in advance in the frame type regulation unit 2. In addition, the protocol type restriction unit 3 stores in advance a list of protocol type information for determining the protocol type.

The output means 4 includes a network interface 4a (network I / F 4a) connected to the network device 20 and a transceiver 4 having a transmitting / receiving function.
b. Here, the transceiver 4b of the output unit 4 and the transceiver 1b of the input unit 1 are directly connected to each other, and the transmission packet Pt output from the network device 20 can be directly issued to the network transmission line N.

The allowable type designation table 5 is stored in a rewritable nonvolatile memory (for example, NVRAM). As shown in FIG. 2, a plurality of frame types and protocol types are described in the allowable type designation table 5, and designation of “restriction” or “permission” is described for each. The example of FIG. 2 indicates that the frame type restriction unit 2 allows only packets having the frame type C to pass, and restricts the passage of packets having other frame types.
Further, it indicates that the protocol type restricting means 3 permits only packets having the protocol type B to pass, and restricts passage of packets having other protocol types.

The designation changing means 6 includes a switch group for switching the designation 5b of the permission type designation table 5 from "permissible" to "restricted" or from "restricted" to "permissible", and the setting change by this switch group. And a control unit for reflecting the contents of the non-volatile memory. The designation changing means 6 may be an external terminal.

In this embodiment, the network device 2
0 is composed of a printer device and a LAN adapter. Here, the network device 20 is not particularly limited as long as it is a device compatible with the network.

Next, the overall operation of the above embodiment will be described.

First, the designation changing means 6 is operated to make the designation 5b of each frame type and protocol type described in the permission type designation table "permissible" in accordance with the frame type and protocol type handled by the network device 20. Alternatively, set it to “Restriction”.

When the packet Pr is taken into the input means 1 from the network transmission line N, the packet is sent to the frame type regulation means 2. The frame type regulation unit 2 receives the packet Pr received from the input unit 1.
The frame type information of the packet is extracted by comparing the frame type information with a list of the frame type information. Subsequently, the frame type restriction unit 2 refers to the allowable type designation table 5 and determines whether the passage of the packet should be “allowed” or “restricted” for the specified frame type. As a result, the packet Pr is input to the protocol type restricting means 3 if it should be “allowed”. On the other hand, if the packet should be “restricted”, the packet is deleted.

The packet P from the frame type regulation means 2
Upon receiving r, the protocol type restriction unit 3 extracts the protocol type information from the frame of the packet Pr and compares it with the list of the protocol type information to identify the protocol type in the packet. continue,
The protocol type restriction unit 3 refers to the allowable type designation table 5 and judges whether the passage of the packet for the specified protocol type should be “allowed” or “restricted”. As a result, if the packet should be “allowed”, the packet Pr is sent to the output means 4. On the other hand, if the packet should be “restricted”, the packet is deleted.

The packet Pr sent from the protocol type restriction means 3 to the output means 4 is output by the output means 4.
It is transmitted to the higher-level network device 20. On the other hand, the transmission packet P issued by the higher-level network device 20
t is taken into the output means 4 and directly input means 1
And transmitted to the network transmission line N.

As described above, according to this embodiment, the frame type restricting means 2 and the protocol type restricting means 3 are provided.
Of the packet Pr randomly picked up from the network transmission path N, only packets having a frame type and a protocol type that can be handled by the upper network device 20 are selectively transmitted to the network device 20 and other packets are transmitted. Is network equipment 20
Since it is restricted to be transmitted to the network device 20
It is possible to prevent a situation in which a packet incompatible with the above interface is transmitted, and to ensure a normal communication operation of the network device 20 in a network that handles a wide variety of packets of different frame types and protocol types. .

Further, since the frame type and the protocol type of the packet which is allowed to be transmitted can be appropriately changed by the designation changing means 6 according to the host network equipment 20, the versatility is high and the packet type can be installed in a wide variety of network equipment. can do.

Here, the frame type restriction means 2, the protocol type restriction means 3 and the allowable type designation table 5
The various functions may be realized as the functions of a micro program that operates on a microcomputer. In addition, the packet restriction device may be installed in the main body of the network device regardless of the present embodiment.

[0032]

Since the present invention is constructed and functions as described above, according to this, the frame type restricting means and the protocol type restricting means can be used in a higher order network device from a packet randomly taken from the network transmission line. Only packets having a frame type and protocol type that can be handled are selectively transmitted to the network device, and other packets are restricted from being transmitted to the network device. It is possible to prevent a situation in which the packet is transmitted, and it is possible to ensure a normal communication operation of a network device in a network that handles various packets having different frame types and protocol types.

Further, when the designation changing means is provided, the frame type and the protocol type of the packet which is allowed to be transmitted can be changed appropriately according to the host network equipment, so that the versatility is high and various types are available. It is possible to provide an unprecedented excellent packet control device that can be installed side by side with a network device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a partially omitted configuration diagram showing details of an allowable type designation table shown in FIG.

FIG. 3 is a partially omitted configuration diagram showing an outline of elements constituting a packet, FIG. 3A illustrates an outline of a packet configuration, and FIG. 3B illustrates an outline of a frame configuration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 input means 2 frame type regulation means 3 protocol type regulation means 4 output means 5 allowable type designation table 6 designation change means 10 packet regulation device 20 network equipment N network transmission line P, Pr, Pt packet

Claims (3)

[Claims] 1. An input means for fetching a packet from a network transmission line, a frame type regulation means for passing only a packet having a frame type permitted in advance among the packets sent from the input means, and the frame type regulation means. A packet having a protocol type permitted in advance among packets that have passed through the protocol type restricting means, and output means for outputting a packet that has passed through the protocol type restricting means to a network device. Packet control device. 2. The packet restriction device according to claim 1, wherein a plurality of types of frame types and protocol types are described, and the frame type and protocol to allow passage of the frame type restriction means or the protocol type restriction means. An allowable type designation table in which type designations are described, wherein the frame type regulation means and the protocol type regulation means permit passage of a packet having a frame type or protocol type designated in the permitted type designation table. Packet control device characterized by. 3. The packet restriction device according to claim 2, further comprising specification changing means for changing the specification of the frame type and the protocol type which are allowed to pass, which is described in the allowable type specification table. Characterized packet control device.