JP2830270B2 - LAN monitor circuit - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a monitor circuit for managing type information of a packet signal on a network.

[Problems to be solved by conventional technology and invention]

Conventionally, monitoring is performed only in a local area network (LAN) of one type of medium access (MAC) method. In particular, in the monitoring of the Ethernet network, monitoring of level 3 frame type information such as TCP-IP and TCP-ARP is also performed. However, monitoring is limited to a network in which communication is performed using one medium access method, and monitoring of a LAN in which packets transmitted from a network using a different medium access method flows, such as the present invention. There was no monitor circuit to perform.

An object of the present invention is to provide a monitor circuit for monitoring a LAN as described above.

[Means for solving the problem]

The present invention relates to a network in which a plurality of networks performing communication by different medium access methods are connected, and the type information of a packet signal is transmitted in a LAN in which MAC level type information is added to the head of a frame transmitted from the network and transmitted. A monitor circuit for managing, comprising: a MAC type detector for detecting type information of a MAC of a packet signal on the network; a layer 3 type detector for detecting type 3 layer information; and the MAC type detector. A frame type generation unit configured to generate one frame type from the detection result of the layer 3 type detection unit; and a recording unit that records the frame type supplied from the frame type detection unit. And manage the MAC type information and the layer 3 type information as one type information. And butterflies.

Further, according to the present invention, the frame type detection unit can generate an alarm when detecting an unregistered frame type.

[Action]

The MAC type detector detects MAC level type information on the network, while the level 3 type detector detects
The MAC type of the received frame detected by the type detector is CSM
If it is an A / CD and it is an Ethernet network,
Perform level 3 type detection. The frame type is generated by the frame type generation unit from the detection results of the MAC type detection unit and the level 3 type detection unit, and stored in the recording unit, so that the MAC level type information and the layer 3 type information are combined into one type information. Manage as

〔Example〕

First, a network to which the present invention is applied will be described with reference to FIGS. As shown in FIG. 2, a network to which the present invention is applied has a form in which a LAN (Ethernet, IEEE standard network, etc.) that performs communication by a plurality of medium access methods is connected to one backbone LAN. . FIG. 3 shows a packet format running on the LAN. As shown in FIG. 3, the packet is transmitted with MAC level type information added to the beginning of the packet. The packet does not have the layer 3 type transmitted from the LAN other than the Ethernet network shown in FIG. 3A, and the packet has the layer 3 type shown in FIG. 3B transmitted from the Ethernet network. There are two types. In the figure, DA is the destination address (Destination Address), SA is the source address (Sou
rce Address).

FIG. 4 shows a correspondence table between the MAC type and the layer 3 type. Only the CSMA / CD type Ethernet network has a layer 3 type, and other MAC types do not have a plurality of layer 3 types.

FIG. 1 is a block diagram showing an embodiment of a frame type monitor circuit according to the present invention. The monitor circuit includes a frame detecting unit 11, a MAC type detecting unit 12, a level 3 type detecting unit 13, a processing unit 14, a memory table 21
And a recording unit 30. Frame detector 11 and MAC type detector 1
2, the level 3 type detection unit 13 and the frame type generation unit 20 constitute a frame type detection unit.

The frame detection unit 11 receives a frame from the transmission path 1. The MAC type detector 12 detects the type information of the MAC level from the received frame, and the level 3 type detector 13 detects the level 3 type information of the packet transmitted from the Ethernet network from the received frame. The memory table 21 in the frame type generation unit 20 includes the MAC type and the level 3
It is a correspondence table of the frame type generated from the type.
The processing unit 14 separates, for example, monitor information such as an address and a packet length from the frame received from the frame detection unit 11. The recording unit 30 records data obtained from the frame type generation unit 20 and the processing unit 14.

The monitor circuit having the above configuration is connected to the backbone LAN as shown in FIG.

 Next, the operation of this embodiment will be described.

The frame detection unit 11 receives a packet traveling on the transmission path 1. The detected frame is the MAC type detector 1
It is transmitted to the 2, level 3 type detection unit 13 and the processing unit 14. The MAC type detection unit 12 detects the MAC type of the frame. When the MAC type of the received frame detected by the MAC type detection unit 12 is CSMA / CD, the level 3 type detection unit 13 detects the level 3 type. However, CSMA
If / CD is not an Ethernet network, there is no level 3 type, so a level 3 type detection unit
At 13, no level 3 frame type is detected.
The results of the MAC type detector 12 and the level 3 type detector 13 are transmitted to the frame type generator 20.

In the memory table 21 in the frame type generation unit 20,
The frame type is generated by reading out the frame type from the correspondence table of the MAC type, level 3 type and frame type registered in advance. At this time, the length N of the frame type is the length of the MAC type and the length of the level 3 type (the type field of the Ethernet network =
16bit) is smaller than the sum.

The processing unit 14 separates, for example, monitor information such as an address and a packet length from the packets received from the frame detection unit 11 and stores the information in the recording unit 30 together with the frame type from the memory table 21. At this time, time information can be added at the time of data storage.

FIG. 5 is a configuration block diagram showing a second embodiment of the present invention. This embodiment differs from the first embodiment shown in FIG. 1 in that an alarm generator 16 is added, and the other configuration is the same as that of the first embodiment. The constituent elements corresponding to the elements are denoted by the same reference numerals.

The alarm generator 16 is for generating an alarm when the monitor circuit detects an unregistered frame type. This makes it possible to detect unregistered MAC types and level 3 types.

Specifically, when the type information received from the MAC type detecting unit 12 and the level 3 type detecting unit 13 is not registered in the memory table 21, the error information is transmitted to the alarm generating unit 16, At the same time as generating an alarm at 16, error information is transmitted to the processing unit 14,
The processing unit 14 separates the SA, MAC type, and level 3 type from the received packet, adds time information, and stores it in the recording unit 30.

In the first and second embodiments, the recording unit 30 writes the detected frame type and the monitor information such as the address and the packet length obtained from the frame. However, as shown in FIG. 6, the recording unit 30 includes a processor 32 and a packet number counter 31 for each frame type.
And the counting result for each frame type classified by the frame type detection unit 20 can also be recorded.

〔The invention's effect〕

As described above, according to the present invention, since the type information of the MAC level and the type information of the level 3 are managed as one type information, the management of the frame type becomes easy. Further, since the length is compressed at the time of generating the frame type, the storage capacity is small.

[Brief description of the drawings]

1 is a block diagram showing a configuration of a first embodiment of the present invention, FIG. 2 is a diagram showing a configuration of a network to which the present invention is applied, FIG. 3 is a diagram showing a frame configuration, and FIG. FIG. 5 is a diagram showing a correspondence table between types and level 3 types, FIG. 5 is a configuration block diagram showing a second embodiment of the present invention, and FIG. 6 is a diagram showing a configuration example of a recording unit. DESCRIPTION OF SYMBOLS 1 ... Transmission line 11 ... Frame detection part 12 ... MAC type detection part 13 ... Level 3 type detection part 14 ... Processing part 20 ... Frame type generation part 30 ... Recording part 31 ... Counter part 32 ... … Processor

Claims (2)

(57) [Claims] 1. A type of packet signal in a LAN where a plurality of networks performing communication by different medium access methods are connected, and MAC level type information is added to the head of a frame transmitted from the network and transmitted. A MAC type detection unit for detecting MAC type information of a packet signal on the network, a layer 3 type detection unit for detecting layer 3 type information, and the MAC type detection A frame type detection unit including a unit and a frame type generation unit that generates one frame type from the detection result of the layer 3 type detection unit; and a recording unit that records the frame type supplied from the frame type detection unit. To manage MAC type information and layer 3 type information as one type information LAN monitor circuit according to claim. 2. The LAN monitor circuit according to claim 1, wherein said frame type detector generates an alarm when detecting an unregistered frame type.