JPH06350608A - Repeater for network - Google Patents

Abstract

PURPOSE:To relay a frame efficiently with inexpensive configuration. CONSTITUTION:The repeater is provided with a bridge function implementing bridging processing based on a destination physical address of a reception frame and with a router function implementing routing processing based on a protocol of a network layer of the received frame. When the received frame is not addressed to the concerned station and a protocol of the network layer of the received frame is a protocol supported by the router function, no bridge processing is executed and the received frame is aborted. Since the number of the received frames requiring the bridging processing is reduced, even when the search of filtering database for the bridging processing is executed by the software processing, a sufficient relay capability is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used when connecting between segments in a local area network, between local area networks, and between a local area network and a wide area network, and functions as a bridge. The present invention relates to a network relay device called a bruta device that also has a function as a router.

[0002]

2. Description of the Related Art There are bridges and routers as internetwork devices for connecting between segments in a local area network and between local area networks, and a bruta device having both of these functions has been conventionally used. . The bruta device performs bridging processing and routing processing. What is bridging processing?
This is a process of deciding whether or not to relay the frame based on the destination address in the received frame, discarding frames that do not need to be relayed, and passing necessary frames. In addition, the routing process is a process in which only the necessary received frames among the received frames supported by the protocol of the network layer are passed through the optimum route.

To perform the bridging process, the bruta device is equipped with a filtering database. For example, it is assumed that the network A and another network B are connected by a bruta device. In this case, when any frame is given from the network A side to the bruta device, the source address in the frame is registered in the filtering database as the address of the node on the network A side. Similarly, when a frame from the network B side is received,
The source address of the frame is registered in the filtering database as the address of the node on the network B side. The contents of this filtering database are updated at regular intervals, and old entries are deleted.

FIG. 8 is a block diagram showing the basic configuration of a bruta device which has been conventionally used. The bruta device includes a CPU 70, and the CPU 70 includes an internal bus 7
1 through the memory 72 and a plurality of LAN controllers 8
.., 8N (hereinafter, collectively referred to as "LAN controller 8") are connected. Each LAN controller 8 is connected to a different local area network, and controls the input / output of information with respect to these local area networks. The above-mentioned filtering database is formed in the memory 72.

Information is transmitted and received for each frame of a predetermined format. The received frame is received by the LAN controller 8 and stored in the memory 72 via the internal bus 71. Further, the transmission frame is transmitted from the LAN controller 8 corresponding to the destination local area network. FIG. 9 is a flow chart for explaining the processing by the bruta device. Frame received, L
When the received frame is written in the memory 72 by the operation of the AN controller 8, the CPU 70 accesses the memory 71 and reads the received frame. Then, in step n1, it is determined whether or not the destination physical address of the frame is addressed to itself. When the received frame is addressed to itself, the network layer protocol of the frame is classified.

In the process of classifying the network work layer protocol, first, the format of the received frame is determined. Then, according to the format of the received frame, the CPU
70 extracts information indicating a protocol from the received frame. The extracted information is compared and collated with the protocol table stored in the memory 72, and the classification of the network layer protocol of the received frame is achieved. It should be noted that the above-mentioned protocol table stores information indicating the protocol of the network layer supported by the bruta device as a router. CPU70
If the information corresponding to the information indicating the protocol extracted from the received frame is not stored in the protocol table, it means that the network layer protocol of the received frame is not supported by the brouter device.

At step n2, it is judged whether or not the classified protocol is one supported by the brouter device as a router. If the protocol is supported as a router, step n3
In step n4, the received frame is discarded when the routing process is performed and the router does not support it. That is, if the destination physical address is that of the own station but does not support the network layer protocol as a router, the received frame is, as it were, an abnormal frame. There is.

On the other hand, when it is determined in step n1 that the physical address of the received frame is not addressed to the own station, the process proceeds to step n5 and bridging processing is performed. In the bridging process, first, in step n5a, the above filtering database is searched. Then, if the destination physical address of the received frame is registered in the filtering database as a node in the network of the side that issued the received frame (the side where the bruta device received the frame (reception side)) (step n5b), proceeding to step n4, the frame is discarded. When the destination physical address is not registered in the filtering database as a node in the network on the receiving side, forwarding processing for passing the frame is performed (step n5c).

[0009]

In the above-mentioned prior art,
Bridging processing using the filtering database is performed on all received frames whose destination physical address is not addressed to itself. Therefore, if the search of the filtering database is performed by software processing, it takes a long time to relay the frame, and sufficient performance cannot be obtained.

In order to solve this problem, it is conceivable to search the filtering database at high speed using dedicated hardware. However, if such a configuration is adopted, there is a new problem that the cost becomes high. On the other hand, in the above conventional technique, the determination of whether or not the received frame is addressed to itself, the determination of the received frame format, and the determination of whether or not the protocol of the received frame is supported are realized by the software processing executed by the CPU 70. Has been done. Therefore, the CPU 70 executes the above processes while accessing the memory 72 and reading the received frame, the address of the own station, and the contents of the protocol table. Therefore, the number of memory accesses by the CPU 70 increases. Moreover, since each of the above processes is generally processed by another program, the number of memory accesses becomes extremely large. Therefore, there is a problem that the processing time for the received frame is very long.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above technical problems and to provide a network relay device capable of efficiently processing received information without increasing the cost excessively.

[0012]

A relay device for a network according to claim 1 for achieving the above object receives and relays information including a destination address and information corresponding to a protocol of a network layer. A relay device for a network having a router function for performing a routing process based on a protocol of a predetermined type of network layer and a bridging function for performing a bridging process based on a destination address. Address determination means that refers to the destination address to determine whether the received information is addressed to itself, and whether the network layer protocol of the received information is a protocol supported by the above router function Protocol determining means to determine that the received information is addressed to the own station, and When it is determined that the protocol of the network layer of the received information is a protocol supported by the router function, it is determined that the routing means that performs the routing process and the received information is the information addressed to the own station, and When it is determined that the network layer protocol of the received information is a protocol that is not supported by the router function, it is determined that the first discarding means discards the received information and the received information is not the information addressed to the own station. And, when it is determined that the network layer protocol of the received information is a protocol supported by the router function, the second discarding means for discarding the received information, and the received information is not the information addressed to the own station. And the network layer protocol of the received information is determined by the router function. When it is determined that the port that is not a protocol, characterized in that it comprises a bridging unit for performing bridging processing.

According to the above configuration, the bridging process is not performed on all the received information that is not addressed to the own station, but the received information that is not addressed to the own station and the protocol is not supported by the router function. The bridging process is performed only on. Therefore, the reception information to be subjected to the bridging processing is reduced, and the relay processing of the reception information can be efficiently performed.

The network relay device according to a second aspect of the invention is characterized in that the router function supports a plurality of types of network layer protocols. In this configuration, the router function supports a plurality of types of protocols, so that the amount of received information that requires bridging processing is further reduced. Thereby, the efficiency of the relay process can be further improved.

According to a third aspect of the present invention, in the network relay device, the bridging means includes a filtering database accumulating information necessary for the bridging processing and means for searching the filtering database by software processing. And If this configuration is adopted, the search of the filtering database is performed not by dedicated hardware but by software processing, which can contribute to cost reduction. Moreover, as described above, since the received information to be subjected to the bridging processing is small, even if the filtering database is searched by software processing, sufficient relay processing capability can be obtained.

According to a fourth aspect of the present invention, there is provided a network relay device in which the address determining means and the protocol determining means are configured by hardware. In this configuration, since it is determined by hardware whether the received information is addressed to the own station and whether the protocol is supported by the router function, these determinations are speeded up. Therefore, the processing efficiency can be further improved.

The hardware-structured protocol determining means is, for example, as described in claim 5, a protocol table storing means for storing information indicating a protocol supported by the router function, and a network from the received information. With reference to the protocol information extraction means for extracting information corresponding to the layer protocol and the stored contents of the protocol table storage means, the protocol corresponding to the information extracted from the received information by the protocol information extraction means is the router function. It can be realized by a configuration including means for determining whether or not it is supported by.

According to a sixth aspect of the present invention, in the network relay device, the processing by the address determination means and protocol determination means of the hardware configuration is performed by the routing means, the first discarding means, the second discarding means and the bridging means. It is characterized in that it is performed in parallel with the processing in. According to this configuration, while routing, discarding, and bridging processing is performed on certain reception information, it is possible to determine whether the address is addressed to the own station and support the protocol for the next reception information. The determination as to whether or not it is performed can be performed in parallel. Thereby, the relay processing efficiency can be improved.

According to a seventh aspect of the present invention, there is provided a network relay device, wherein reception information storage means for storing the reception information, reception information writing means for storing the reception information in the reception information storage means, and reception information for the reception information are stored in the reception information storage means. In parallel with the storage in the reception information storage means, it further comprises means for supplying the reception information to the address determination means and the protocol determination means.

According to this structure, the storage of the reception information in the reception information storage means and the supply of the reception information to the address determination means and the protocol determination means are performed in parallel. Thereby, the efficiency of the relay process can be improved. The network relay device according to claim 8 performs any one of a routing process, a discarding process, and a bridging process on the received information based on the determination result of the address determining unit and the determination result of the protocol determining unit. It further includes a processing determination means having a hardware configuration for determining whether to perform it and outputting a signal corresponding to the determination result, wherein the routing means, the first discarding means, the second discarding means, and the bridging means, It is characterized in that processing is performed based on the output signal of the processing determination means.

According to this configuration, the processing determination means of the hardware configuration determines which of the routing process, the discarding process, and the bridging process should be performed on the received information. The process is decided promptly. Thereby, the relay processing can be speeded up.

[0022]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 2 is a block diagram showing a basic configuration of a bruta device which is a network relay device according to an embodiment of the present invention. The bruta device 10 includes a plurality of local area networks NET1, ..., NE.
Intervened between Tk and local area network NE
, For relaying information transferred between NETk.

Inside the bruta device 10, there is provided a CPU 11 (central processing unit) as a routing means, a first discarding means, a second discarding means and a bridging means. The CPU 11 is connected to an internal bus 12. The internal bus 12 has a memory 13, which functions as a reception information storage unit, and an address protocol determination circuit 1.
4, local area network NET1, ..., NE
A plurality of LAN controllers 21 corresponding to Tk, ...
2k (hereinafter, LAN controller 2 when collectively referred to)
Say. ) Is connected.

The bruta device 10 has a router function for determining an optimum relay route based on a network layer protocol and routing (passing) a received frame, and a bridge for performing a bridging process on the received frame based on a destination physical address. It has functions and. In this embodiment, the router function supports a plurality of types of protocols. Further, the bruta device 10 is provided with an address representing the device.

The received frame is stored in the memory 13 by the function of the LAN controller 2 which functions as a received information writing means. At this time, in parallel with the writing process of the received frame to the memory 13, the received frame and the storage address of the memory 13 are given to the address protocol determination circuit 14. Address protocol determination circuit 14
Is for determining whether or not the destination of the received frame is addressed to itself, and for determining the network layer protocol of the received frame. The processing result for each received frame is stored in the memory 13 of the received frame. The address and the address are notified from the FIFO (first-in first-out memory) 14A to the CPU 11 via the internal bus 12.

Upon receipt of the notification from the address protocol determination circuit 14, the CPU 11 performs routing processing and bridging processing for each received frame. This CPU
The processing in 11 is performed by the address protocol determination circuit 14
The process is performed in order from the end of the process. CPU
Even during the processing in 11, the address protocol determination circuit 14
Performs processing for the next received frame in parallel.

FIG. 3 is a diagram showing an example of the structure of a frame relayed by the bruta device 10. Figure 3 (a) shows ETH
ER frame, FIG. 3 (b) shows an IEEE802.3 SNAP frame, and FIG. 3 (c) shows IEEE802.
3 shows three LLC frames. The frame of information to be relayed includes a header part H which is a field for management information and a data part D which is a field for the main body DATA of the information to be transferred. The header part H contains a destination physical address DA that represents the physical address of the destination node.
(6 bytes), the source physical address SA (6 bytes) that represents the physical address of the source node, and the information D individually set corresponding to the protocol such as the network layer.
P and are included.

FIG. 4 is a diagram showing the structure of the ETHER frame in detail. In the ETHER frame, the 13th byte and the 14th byte of the header part are fields for the information TYPE corresponding to the information DP indicating the protocol. This information TYPE represents the type of data unit included in the ETHER frame. Figure 5 shows the IEEE
802.3 SNAP frame and IEEE 802.3
FIG. 3 is a diagram showing a detailed structure of the LLC frame of FIG. The header parts of these two frames have a common configuration up to the 17th byte. The 1st to 12th bytes are fields for the physical addresses DA and SA of the destination and the source, the 13th and 14th bytes are fields for the information LEN indicating the data length,
The 15th byte is information DSAP (Desti) indicating the destination address.
nation service access point), the 16th byte is information SSAP indicating the source address.
It is a field for (Source Service Access Point), and the 17th byte is a field for control information C. These pieces of information DSAP, SSAP and C form a logical link control protocol data unit LLC.

In the IEEE802.3 SNAP frame, the 18th to 20th bytes are assigned to the protocol identification information OUI, and the 21st and 22nd bytes are information T for indicating the type of the data unit.
Assigned to YPE. In addition, IEEE802.
In the LLC frame of No. 3, the 18th and subsequent bytes are fields for the main body DATA of the information to be transmitted. The information OUI and TYPE form the format identification information SNAP.

The memory 13 provided in the bruta device 10
A filtering database for bridging processing is stored therein. For example, Bruta device 1
0 to the local area network NET i (i =
1, 2, ..., K), a source physical address SA in the frame is registered in the filtering database as an address of a node on the local area network NETi side with respect to the bruta device 10. To be done. The contents of this filtering database are updated at regular intervals, and old entries are deleted.

FIG. 6 is a block diagram showing the configuration of the address protocol determination circuit 14. The address protocol determination circuit 14 is realized by a hardware configuration, and determines whether or not the received frame is a frame addressed to itself based on the destination physical address DA in the received frame given from the LAN controller 2. Function to
It has a function of determining the protocol of the network layer and determining whether or not the protocol is supported by the router function of the device.

More specifically, the received frame from the LAN controller 2 has a header block extracting section 41.
Given to. The header block extraction unit 41 uses the physical address DA, in the three types of frames shown in FIG.
The header block HB includes a portion in which SA and information DP corresponding to each type of protocol may be stored.
(See FIG. 3. 22 bytes starting from the physical address). Then, the portion of the destination physical address DA of the extracted header block HB (the first 6
Byte) to the destination address determination unit 42. A ROM (Read Only Memory) 43 that stores the physical address assigned to the bruta device 10 is connected to the destination address determination unit 42. Destination address determination unit 42
Determines whether the received frame is addressed to its own station by collating the address stored in the ROM 43 with the destination physical address DA given from the header block extraction unit 41, and the determination result is processed. Give to part 44.

On the other hand, the header block extraction unit 41 determines the physical address D of the extracted header block HB.
The portion other than A and SA (the 13th byte to the 22nd byte of the header block HB) is set to the protocol display data extracting unit 4.
Give to 5. The protocol display data extraction unit 45 extracts the protocol display data representing the protocol in the received frame based on the given information. The extracted protocol display data is the information TYPE in the case of the ETHER frame, and is the SNAP of IEEE802.3.
In the case of a frame, the information is TYPE in the format identification information, and in the case of an IEEE802.3 LLC frame, the information is LEN and LLC.

The extracted protocol display data is given to the protocol support judging section 47. The protocol support determination unit 47 stores protocol tables supported by the router function of the bruta device 10 as a table, which is a protocol table storage unit 51, 52, 53.
Are connected. The protocol table storage unit 51 stores a table of protocols represented by the protocol display data stored in the fields of the above information TYPE. The protocol table storage unit 52 stores information DSA in the logical link control protocol data unit LLC of the IEEE802.3 frame.
A table of protocols represented by P is stored, and the protocol table storage unit 53 stores IEEE8
02.3 SNAP frame format identification information SN
A table of protocols represented by the information OUI in the AP is stored.

The protocol support determination unit 47 checks whether or not the protocol corresponding to the protocol display data extracted by the protocol display data extraction unit 45 is stored in the protocol table storage units 51, 52, 53, thereby receiving the received frame. Is determined by the router function of the bruta device 10. A signal corresponding to this determination result is given to the processing determination unit 44.

The protocol support judgment unit 47 also
A protocol identifier corresponding to the protocol display data,
The frame type identifier corresponding to the format of the received frame is given to the FIFO 14A from the line 46. Which of the discard process, the routing process, and the bridging process is appropriate for the received frame based on the determination results of the address determination unit 42 and the protocol determination unit 47. To decide. The determination result of the processing determination unit 44 is the FIFO.
14A.

In the FIFO 14A, the storage address of the received frame in the memory 13 (see FIG. 2) is the LAN
It is provided from the controller 2 via line 50. Then, in the FIFO 14A, for each received frame,
The storage address in the memory 13, the determination result of the processing determination unit 44, the protocol identifier, and the frame type identifier are stored in association with each other. Since the address protocol determination circuit 14 has a hardware configuration, its internal processing is instantaneously performed. Therefore, the storage address from the line 50 and the outputs of the processing determination unit 44 and the protocol support determination unit 47 can be easily associated and stored in the FIFO 14A.

The data stored in the FIFO 14A is given to the CPU 11 via the internal bus 12. Figure 7
FIG. 6 is a diagram for explaining details of processing in a protocol display data extraction unit 45 and a protocol support determination unit 47. First, in the processing block m1, the 13th byte and the 14th byte in the header block HB (as is clear from FIG. 3 and the like, information TYPE is set in this field).
Alternatively, LEN is stored. ) Is referred to, and it is checked whether or not the information TYPE is stored in this field. When the information TYPE is stored, the 13th byte and the 14th byte in the header block HB are extracted as protocol display data (processing block m2). Further, the TYPE field protocol table storage unit 51 is searched based on the extracted protocol display data (processing block m3), and the protocol identifier corresponding to the protocol display data and the protocol are supported by the router function of the bruta device 10. A signal is generated indicating whether or not (processing block m4).

In the processing block m5, the information in the fields of the 13th and 14th bytes is the information TYP.
Based on E, the received frame is determined to be an ETHER frame, and a signal corresponding to the determination result is output. On the other hand, if the information in the fields of the 13th and 14th bytes is not the information TYPE,
In processing block m6, 15th byte storing information DSAP, 1st byte storing information SSAP
The 6th byte and the 17th byte where the information C is stored are referred to. DSAP is “AAh” (h is a symbol representing hexadecimal number), and SSAP is “AAh”.
h "and C is" 03h ". If all these conditions are satisfied, then
The information in the Byte, 16th Byte and 17th Byte fields is the control information LLC and therefore the received frame is an IEEE 802.3 frame. In this case, the processing moves to the processing block m7.

In processing block m7, it is checked whether all the information OUIs in the format identification information SNAP are "00h". If this condition is met, the received frame is an IEEE 802.3 SNAP frame. Therefore, in the processing block m8, the 21st and 22nd bytes of information TYPE are extracted as protocol display data, and in the processing block m9, the TYPE field protocol table storage unit 51.
Will be searched. Subsequent processing moves to processing block m4.

Information O in the processing block m7.
When it is determined that all the UIs are "00h", the received frame is an IEEE802.3 SNAP frame, so the frame type determination process in the processing block m5 is performed. When it is determined in the processing block m7 that all the information OUIs are not "00h", the processing proceeds to the processing block m10. Processing block m
In 10, the information OUI stored in the 18th byte, 19th byte, and 20th byte fields is extracted as protocol display data. Then, the OUI display protocol table storage unit 52 is searched using the extracted protocol display data (processing block m11). Subsequent processing moves to processing block m4.

If the above conditions are not met in processing block m6, processing block m13
The 15th byte of information DSAP is extracted as protocol display data. Using this, the DSAP display protocol table storage unit 52 is searched. Subsequent processing moves to processing block m4. In this way, the format of the received frame is checked, and appropriate protocol display data is extracted according to the format. Then, based on the extracted protocol display data, the protocol table storage units 51, 52, 53 are searched to check whether or not the network layer protocol of the received frame is supported by the router function of the bruta device 10. Become.

FIG. 1 is a flow chart for explaining the operation of the bruta device 10. Note that the processing within the range 60 shown by the broken line in FIG. 1 is processing performed in the address protocol determination circuit 14. When a frame is received from the local area network NETi, the destination address determination unit 42 in the address protocol determination circuit 14 determines whether the received frame is addressed to itself. Further, the protocol support determination unit 47 determines whether or not the network layer protocol of the received frame is a protocol supported by the router function of the bruta device 10.

Based on these judgment results, the processing judgment unit 44 in the address protocol judgment circuit 14 first
It is determined whether the received frame is addressed to the own station (step S1). If the received frame is addressed to its own station, step S2
At, it is determined whether the network layer protocol of the received frame is a protocol supported by the router function of the bruta device 10. When the protocol of the received frame is supported by the router function, the processing determination unit 44 outputs a signal indicating that the routing processing should be performed.

This signal is sent to the CPU via the FIFO 14A.
When it is given to 11, the CPU 11 performs the routing process in step S3. That is, the optimum route is determined, and the received frame is relayed from one local area network to another local area network according to the determined route. In this case, CP
The U11 identifies the received frame to be processed based on the storage address given from the FIFO 14A. That is, the address given from the FIFO 14A is accessed to read the received frame from the memory 13, and the received frame is subjected to routing processing. It should be noted that even during the period when such processing is being performed by the CPU 11, the processing for the next received frame is proceeding in parallel in the address protocol determination circuit 14.

When the protocol of the received frame is not supported by the router function, the processing judgment unit 44
Outputs a signal indicating that the received frame should be discarded. When this signal is given from the FIFO 14A to the CPU 11, the CPU 11 discards the received frame in step S4. That is, even though the destination physical address of the received frame is addressed to itself, if the protocol of the received frame is not supported by the router function, such a received frame is considered to be an abnormal frame. To be Therefore, such frames are discarded.

On the other hand, if it is determined in step S1 that the destination physical address of the received frame is not the local station, the network layer protocol of the received frame is supported by the router function of the bruta device 10 in step S5. It is determined whether it is a protocol. If the protocol is supported by the router function, the processing determination unit 44 outputs a signal indicating that the received frame should be discarded. This signal is FIFO
When given from the 14A to the CPU 11, the CPU 11 discards the received frame in step S4. That is, even though the router function of the bruta device 10 supports the protocol of the received frame, if the received frame is not addressed to itself, it is not necessary to pass the received frame. Such received frames are to be discarded.

When it is determined in step S5 that the protocol of the network layer of the received frame is not the protocol supported by the router function of the bruta device 10, the processing determination unit 44 performs the bridging process on the received frame. Outputs a signal indicating that This signal is sent from the FIFO 14A to the CPU 1
When it is given to 1, the CPU 11 performs the bridging process in step S6. That is, when the router function does not support the protocol, it is not known whether or not the received frame that is not addressed to the own station may be discarded. Therefore, further bridging processing is performed.

In the bridging process, first, the CPU 11
Searches the above-mentioned filtering database (step S61). If the destination physical address DA of the received frame is registered in the filtering database as the local area network side (reception side) node that issued the received frame (step S6).
2) The received frame is discarded (step S)
4). On the other hand, when the destination physical address of the received frame is not registered in the filtering database as the receiving side node (step S62), step S63.
At, the forwarding process is performed on the received frame. That is, the received frame is transferred to a local area network different from the receiving side.

As described above, according to the present embodiment, all received frames other than those addressed to the own station are not addressed to the own station, and the protocol is supported by the router function. The bridging process is performed only on the received frames that have not been received. Therefore,
The number of received frames that require bridging processing is significantly reduced compared to the conventional configuration. Therefore, the number of times the filtering database is searched decreases. as a result,
Although the search of the filtering database is performed by the software processing of the CPU 11, the time required for the bridging processing can be reduced. Therefore, since it is not necessary to use dedicated hardware for searching the filtering database, relay processing with high processing efficiency can be performed at low cost.

Moreover, since the router function of the bruta device 10 of this embodiment supports a plurality of types of protocols, it is possible to extremely reduce the number of frames that require bridging processing. This also improves the efficiency of relay processing. Further, in the present embodiment, the determination of whether or not the received frame is addressed to the own station and the determination of whether or not the network layer protocol of the received frame is supported by the router function of the bruta device 10 are configured by hardware. Address protocol determination circuit 1
It is done by 4. Therefore, which of discarding, routing, and bridging should be performed on the received frame is promptly determined. Also, the number of times the CPU 11 accesses the memory 13 is reduced. As a result, the relay process can be performed at extremely high speed, and a bruta device with high processing capability can be realized.

Moreover, at the time of receiving a frame, while the received frame is stored in the memory 13, the determination process regarding the address and the protocol for the received frame is performed in parallel. Also, the processing in the CPU 11 and the processing in the address protocol determination circuit 14 are performed in parallel. By these things, the speed of the relay process can be increased.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, in the above embodiment, the hardware configuration is used to determine whether the received frame is addressed to the own station and whether the protocol of the received frame is supported by the router function. Both or either of the above determinations may be realized by software processing.

In the above embodiment, the bruta device 1 is used.
The router function of 0 supports a plurality of types of protocols, but the router function of the bruta device may support one type of protocol. Further, in the flowchart shown in FIG. 1, it is first judged whether or not the received frame is addressed to the own station, and then it is judged whether or not the protocol is supported by the router function. , And these two determinations may be performed first. The order of determination depends on the internal hardware configuration of the processing determination unit 44.

In the above embodiment, the bruta device for connecting the local area networks has been described as an example, but the present invention relays between the segments in the local area network or between the local area network and the wide area network. It is also applicable to bruta devices.
In addition, various design changes can be made without changing the gist of the present invention.

[0056]

As described above, according to the network relay device of the present invention, the bridging process is performed only on the received information which is not addressed to the own station and whose protocol is not supported by the router function. Therefore, the received information subject to bridging processing is reduced. As a result, the relay processing of the received information can be efficiently performed.

Moreover, since the received information to be subjected to the bridging process is small, as described in claim 3, even if the filtering database storing the information necessary for the bridging process is searched by the software process. , It is possible to secure sufficient relay capacity. This allows
Since it is not necessary to use dedicated hardware for searching the filtering database, it is possible to contribute to cost reduction.

According to the second aspect of the invention, since the router function supports a plurality of types of protocols, the received information that requires bridging processing is further reduced. Therefore, the efficiency of relay processing can be further improved. According to the invention described in claim 4 or 5, the hardware configuration determines whether the received information is addressed to the own station and whether the protocol is supported by the router function. The determination can be speeded up and the processing efficiency can be further improved.

According to the sixth aspect of the present invention, while performing the routing process for certain reception information, the address determination process and the protocol determination process are performed in parallel for the next received information. You can Thereby, the relay processing efficiency can be improved. Claim 7
According to the invention described above, since the received information can be supplied to the address determination means and the protocol determination means in parallel with the storage of the received information in the received information storage means, the efficiency of the relay processing can be improved.

According to the invention described in claim 8, the processing to be applied to the received information is judged at high speed by the processing judging means of the hardware structure, so that the relay processing can be speeded up.

[Brief description of drawings]

FIG. 1 is a flowchart for explaining the operation of a bruta device that is a network relay device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of the bruta device.

FIG. 3 is a diagram showing a structure of a reception frame.

FIG. 4 is a diagram showing a structure of an ETHER frame.

FIG. 5 is a diagram showing the structure of an IEEE 802.3 frame.

FIG. 6 is a block diagram showing a configuration of an address protocol determination circuit.

FIG. 7 is a diagram for explaining an internal process of an address protocol determination circuit.

FIG. 8 is a block diagram showing a configuration of a conventional bruta device.

FIG. 9 is a flowchart for explaining the operation of the conventional bruta device.

[Explanation of symbols]

21, ..., 2k LAN controller 10 Bruter device 11 CPU 13 Memory 14 Address protocol determination circuit NET1, ..., NETk Local area network 41 Header block extraction unit 42 Destination address determination unit 44 Processing determination unit 45 Protocol display Data extraction unit 47 Protocol support determination unit

Claims (8)

[Claims] 1. A router function, which is used to receive and relay information including a destination address and information corresponding to a network layer protocol, and which performs a routing process based on a predetermined type of network layer protocol, and a destination. A network relay device having a bridging function that performs a bridging process based on an address, and refers to a destination address of received information to determine whether the received information is addressed to itself. Means for determining whether the network layer protocol of the received information is a protocol supported by the router function, and the received information is determined to be information addressed to the own station, and the received information Network layer protocols supported by the above router function If it is determined that there is a routing means for performing a routing process, it is determined that the received information is addressed to its own station, and the protocol of the network layer of the received information is not supported by the router function. When it is determined that the received information is the first discarding means, the received information is not the information addressed to the own station, and the network layer protocol of the received information is supported by the router function. Second discarding means for discarding the received information when it is determined that the received information is not addressed to the own station, and the protocol of the network layer of the received information is the router function. Bridging that performs bridging when it determines that the protocol is not supported by Network relay apparatus characterized by comprising a means. 2. The network relay device according to claim 1, wherein the router function supports a plurality of types of network layer protocols. 3. The bridging means includes a filtering database in which information necessary for bridging processing is stored, and means for searching the filtering database by software processing. Network relay device. 4. The network relay device according to claim 1, wherein the address determination means and the protocol determination means are configured by hardware. 5. The protocol determining means is a protocol table storing means for storing information representing a protocol supported by the router function, and a protocol information extracting means for extracting information corresponding to a network layer protocol from received information. And a means for determining whether or not the protocol corresponding to the information extracted from the received information by the protocol information extraction means is supported by the router function by referring to the stored contents of the protocol table storage means. The network relay device according to claim 4, wherein: 6. The processing by the address determining means and the protocol determining means of the hardware configuration is performed in parallel with the processing in the routing means, the first discarding means, the second discarding means and the bridging means. 6. The network relay device according to claim 4 or 5. 7. Reception information storage means for storing the reception information, reception information writing means for storing the reception information in the reception information storage means, and storage of the reception information in the reception information storage means in parallel. do it,
7. The network relay device according to claim 4, further comprising means for supplying received information to the address determination means and the protocol determination means. 8. Based on the judgment result of the address judging means and the judgment result of the protocol judging means, it is judged which of the routing processing, the discarding and the bridging processing should be performed on the received information. And further includes a processing determination means having a hardware configuration for outputting a signal corresponding to the determination result, wherein the routing means, the first discarding means, the second discarding means, and the bridging means output the processing determination means. The network relay device according to any one of claims 1 to 7, wherein processing is performed based on a signal.