JPH0522294A - Mac bridge control system - Google Patents

Abstract

PURPOSE:To control occurrence of an undesired track to a low speed WAN connecting to a high speed LAN. CONSTITUTION:The relation of cross reference between a MAC address and a port to which a local network (LAN) line in a MAC bridge provided with a learning table is indicated, the bridge 1 is provided with a LAN table 11 having no refresh function and a WAN table 12 corresponding to a port connecting to a public network line (WAN line), and on the opportunity of a point of time when power is applied to the MAC bridge, the content of the LAN table 11 is exchanged with the MAC bridge of a destination connecting to a port to which the WAN line is connected, an address of a LAN terminal equipment connecting to the MAC bridge in excess of the WAN line is recognized and registered in the WAN table 12 and when an output port is not selected by the address of the learning table, the WAN table 12 is retrieved and when the registered terminal equipment is selected, the frame is transferred to the terminal equipment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer control method for transferring a frame transmitted from a terminal of a certain port to a partner terminal in a MAC bridge having a learning table.

With the recent increase in the speed of computers, the types of local area networks (hereinafter referred to as LANs) have been diversified, and it has become necessary to connect LANs having significantly different communication speeds.

For this reason, it has become necessary to filter the low-speed line by minimizing the load concentrated on the high-speed LAN. Also, as the LAN becomes faster, the number of terminals connected to the LAN is also increasing, and it is required to avoid measures such as setting the position to connect to the LAN line for each specific terminal. It That is, it is desirable that there is no limit on the number of terminals connected to the high speed line or the low speed line.

[0004]

2. Description of the Related Art FIG. 2 is a diagram for explaining a conventional MAC bridge control system, in which (a) shows an example of a MAC address configuration and (b) shows an example of a frame format. In the conventional MAC bridge 1, when connecting LANs connected to multiple ports, it is common to use learning function to discard unnecessary frames.

That is, the MAC bridge 1 receives a frame transmitted from a terminal (for example, a terminal T1) connected to a certain port of the MAC bridge 1, and the MA in the frame is received.
Read the C address (sending address: SA). {Fig. 2
See (b)} Learning table 1 with the read MAC address
Search from 0 to see if it is a registered terminal.

If registered, the value of the timer
Rewrite (the timer value is registered for each port at the time of initial setting). The registered MAC address is erased from the learning table 10 when the time of the timer value has elapsed, and is re-registered when a frame is newly transmitted from the port. (That is, the learning table 10 has a refresh function.)
If the terminal that has transmitted the frame is not registered, the learning table 10 is set by setting the MAC address, port number, and timer value.

As described above, learning is performed by registering the terminal that has transmitted. In this state, the MAC bridge 1 receives the frame from the LAN terminal T1,
The partner MAC address (DA) in the frame is read, the read partner MAC address (reception address: DA) is searched from the learning table 10 and its output port is selected.

In the above search, if the learning table 10 does not have the port having the target MAC address, the frame is transmitted to all ports other than the receiving port.

[0009]

Therefore, in the conventional method, a low speed line, for example, a public network line (hereinafter,
If the port to which (WAN) is connected is not registered in learning table 10 above, as described above, frame transmission to all ports, except the receiving port, and thus to the WAN that is the low-speed line There was a problem that frame transmission to the connected terminal T4 etc. would occur, causing unnecessary traffic to the low speed line.

This is the MAC address (D
The frame with A) is due to the constraint condition of the learning function that it is broadcast to all ports. In view of the above-mentioned conventional drawbacks, the present invention provides a MAC bridge control method capable of controlling a low-speed WAN connected with a high-speed LAN so as not to generate unnecessary traffic in a MAC bridge equipped with a learning table. It is intended to be provided.

[0011]

FIG. 1 is a diagram showing an embodiment of the present invention. The above problems can be solved by the MAC bridge control method configured as follows.

MAC bridge 1 with learning table 10
Shows the correspondence between the port connecting the LAN line and the MAC address, and does not have the refresh function.
Provide a LAN table 11 and a WAN table 12 corresponding to the port to which the WAN line is connected, and connect to the port to which the WAN line is connected when the power of the MAC bridge 1 is turned on. The contents of the LAN table 11 above are exchanged with the destination MAC bridge 1 to identify the address (MAC address) of the LAN terminal connected to the destination MAC bridge 1 of the WAN line. , Register in the WAN table 12 corresponding to the above port,
When the output port cannot be selected by searching the learning table 10 above, the WAN table 12 above is searched, and when the registered terminal can be selected, the frame is transferred to that terminal and the WAN table 12 above is searched. , When the registered terminal cannot be selected, the frame is controlled so as to be discarded.

[0013]

In the present invention, the learning table 10 is provided.
The MAC bridge 1 shows the correspondence between the port connecting the LAN line and the MAC address, and provides the LAN table 11 without the refresh function and the WAN table 12 corresponding to the port to which the WAN line is connected. For example, when the MAC bridge 1 is powered on, or periodically, the contents of the above LAN table 11 held by the MAC bridge 1 to which the WAN line is connected are exchanged, and By registering in the WAN table 12 provided for each port, the MAC address of the LAN terminal of the MAC bridge 1 connected to the WAN line is always maintained.

Therefore, in the conventional method, when a transmission frame is generated from a certain port and the MAC address of the transmission destination of the frame is not registered in the learning table 10, all ports except the port receiving the frame are transmitted. In contrast to the case where the transmission frame was broadcast to the network, in the present invention, when the learning table 10 is searched and the MAC address (DA) of the transmission destination cannot be detected, the WAN
When the table 12 is searched and the MAC address of the destination can be detected there, the frame is transmitted to the port. When the MAC address of the destination is not detected in the WAN table 12, the frame is transmitted. Since the information is discarded, there is an effect that unnecessary traffic on the low-speed WAN line can be suppressed.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 described above is a diagram showing an embodiment of the present invention.

In the present invention, in the MAC bridge 1 having the learning table 10, the correspondence between the port connecting the LAN line and the MAC address is shown, and the LAN table 11 having no refresh function and the WAN line are shown. A WAN table 12 corresponding to the connected port is provided, and when the power of the MAC bridge 1 is turned on, the MAC bridge of the destination connected to the port to which the WAN line is connected is triggered. Between the above LAN table
Exchange the contents of 11 and replace the MAC bridge on the other side of the WAN line.
Recognize the address of the LAN terminal connected to 1 and
Register in AN table 12 and use the above learning table 10
When the output port cannot be selected in the search of, the WAN table 12 above is searched, and when the registered terminal can be selected, the frame is transferred to that terminal and the WAN table 1
Even when the terminal 2 cannot be selected, means for discarding the frame is necessary for implementing the present invention.
The same reference numerals denote the same objects throughout the drawings.

The MAC bridge control method of the present invention will be described below with reference to FIG. MAC bridge in the present invention 1
In addition to the conventional learning table 10, a LAN table 11 without a refresh function and a WAN table 12 for each port to which a WAN circuit is connected are provided. Since the learning method of the learning table 10 does not particularly replace the conventional method, it is omitted here.

Then, the learning of the LAN table 11
When the MAC bridge 1 receives the frame sent from the LAN terminal, its MAC address (SA) ("00000E000001",
~) Is read, and the read MAC address and port number (1, ~) are registered in the LAN table 11. However, no timer is set for this LAN table 11.
That is, the refresh function is not provided.
Alternatively, when power is supplied to the MAC bridge 1,
The system may set it by itself.

The point is that it is connected to the MAC bridge 1.
It only has to function as a table for registering MAC addresses of LAN terminals. Next, the learning of the WAN table 11 is performed, for example, when the MAC bridge 1 connected by WAN connects a line, the contents of the LAN table 11 provided in each of the above with the MAC bridge 1 are learned. Replace and set the WAN table 12 provided for each port.

For example, LAN terminal T4 ("00000E000007") under the MAC bridge connected to the WAN line of port 4
LAN table provided by the MAC bridge to which the LAN terminal T4 is connected when a frame is transmitted from
The contents of 11 are exchanged with the contents of its own LAN table 11, the MAC address of the LAN terminal of the WAN line destination of the port 4 is recognized, and the WA provided corresponding to the port 4 is recognized.
N Set to table 12. The same applies to port 5.

Alternatively, when the MAC bridge 1 is powered on, the MAC bridge connected to the WAN is triggered.
The contents of each LAN table 11 may be exchanged with the first and the second.

Further, the MA connected by the WAN is set at regular intervals.
The contents of each LAN table 11 may be exchanged with the C bridge 1. Hereinafter, the MAC of the present invention
The routing method in bridge 1 is explained.

First, the MAC bridge 1 receives a frame transmitted from a certain port and reads the MAC address (DA) of the partner terminal in the frame. Based on the read MAC address (DA) of the other terminal, the learning table 10 is searched and the output port is selected.

When the output port cannot be selected in the learning table 10, that is, when the port of the terminal is not specified in the learning table 10, in the present invention, the WAN table 12 provided for each port is searched. When it is detected that the MAC address of the partner terminal is registered, the frame is transmitted to the corresponding port, but when the MAC address of the partner terminal is not registered, the frame is discarded.

Therefore, the MA of the other terminal is added to the learning table 10.
When the C address is not registered, conventionally,
Since frames were sent to all ports except the port that received the frame, if a low-speed line such as a WAN is connected to it, there is a problem that unnecessary traffic will occur to the low-speed line. However, in such a case, in the MAC bridge 1 of the present invention, the WAN table 11 of the corresponding port is searched and the WAN table 11 is searched.
Since the MAC address of the LAN terminal registered in is searched, unnecessary traffic for low-speed lines does not occur unlike the conventional method.

[0026]

As described above in detail, according to the present invention,
The MAC bridge control method is a MAC bridge equipped with a learning table, and the MAC
It shows the correspondence relationship with the address and provides a LAN table without a refresh function and a WAN table corresponding to the port to which the WAN line is connected, and when the MAC bridge is powered on, etc. The contents of the above LAN table are exchanged with the destination MAC bridge connected to the port to which the WAN line is connected, and the address of the LAN terminal connected to the destination MAC bridge of the WAN line is exchanged. When the output port cannot be selected by searching the learning table and the registered port can be selected by searching the WAN table, the frame is registered to that terminal. The frame is discarded when the terminal is transferred and the WAN table cannot be selected. Therefore, it is economical and unnecessary traffic to a low-speed line with a small number of terminals. This has the effect of avoiding the occurrence of.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating a conventional MAC bridge control method.

[Explanation of symbols]

1 MAC bridge 10 Learning table 11 LAN table 12 WAN table LAN connected port WAN connected port

Claims (1)

What is claimed is: 1. A MAC bridge having a learning table (10).
In (1), the port connecting the LAN line () and L
It shows the correspondence with the address (MAC address) of the AN terminal, and the LAN table (11) that does not have the refresh function and W
A WAN table (12) corresponding to the port () to which the AN line is connected is provided, and when the power of the MAC bridge (1) is turned on,
The contents of the LAN table (11) above are exchanged with the destination MAC bridge (1) connected to the port () to which the WAN line is connected, and the destination MAC bridge of the WAN line is exchanged. Recognize the address (MAC address) of the LAN terminal connected to (1), register it in the WAN table (12) corresponding to the above port (), and search the learning table (10) above for the output port. If you cannot select it, search the WAN table (12) above, and if you can select a registered terminal, transfer the frame to that terminal, search the WAN table (12) above, and register the registered terminal. The MAC bridge control method is characterized in that the frame is controlled so as to be discarded when it has not been selected.