JPH06216905A - Line concentrator with network management function - Google Patents

Abstract

PURPOSE:To properly collect information regardless of the presence of a station connected through a repeater by holding the address which is finally received by each input port and is used by the high-order protocol of the transmission source station in a frame. CONSTITUTION:Every time the frame transmitted by a station 104 is arrived, a line concentrator 102 internally holds the IP address of the transmission source station written in the IP header of the frame. Since a router 103 relays the frame without rewriting the IP address of the transmission source in the frame at the time of relaying the frame from the station 104 to the line concentrator 102, the line concentrator 102 holds the IP address of the station 104. When the frame arrives at a designated input port, the line concentrator 102 immediately transmits the IP address of the transmission source station of the received finally with this input port to a management station 101. Consequently, the management station 101 collects the information of the station 104.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concentrator with a network management function that collects station information and transmits it to a management station, and in particular, can properly collect information even when there is a station via a relay device. The present invention relates to a concentrator with a network management function.

[0002]

2. Description of the Related Art A concentrator having a plurality of input / output ports is provided to configure a network such as the Internet, and a station is connected to each port of the concentrator. It is also practiced to connect a relay device to the concentrator, and to connect stations in other network segments to the concentrator via the relay device.

In addition, when a plurality of stations are connected to a network, a management station is provided in the network and the network is managed by the management station. The management station is also connected to the port of the concentrator.

In order to support the management at the management station, the concentrator may be provided with a network management function. In the conventional technology, in order for the management station to recognize the network configuration, the concentrator holds the address of the source station used by the lower protocol in the last received frame for each port and manages it. The retained address is transmitted to the management station in response to a request from the station. Here, the address of the source station used in the lower protocol in the received frame is the MA of the source station on the Internet.
It indicates a C address (hardware address).

FIG. 4 shows the protocol structure and FIG. 5 shows the frame structure. In such a hierarchical structure, only the IP header is used for processing in IP and MA is used for processing in MAC
It is done only in the C header.

Further, in the conventional technique, in order to confirm the communication operation of a station inside or outside the network, the management station transmits a frame for confirming the communication operation to the station, and a response from the station. To get.

[0007]

By the way, when a station of another network segment is connected to the concentrator via a relay device and the transmission is performed from the station to the network segment of the concentrator side, the transmission source The station cannot receive the frame to the communication partner unless it goes through the relay device.
In the transmission frame, write the hardware address of the source station (its own) and the IP address of the source station as the source information, and the hardware address of the relay device and the IP address of the partner station as the destination information and transmit. To do. When the relay device receives this frame, it converts the hardware address of the transmission source station into the hardware address of itself (relay device) as the information of the transmission source and the hardware address of the relay device as the hardware information of the partner station as the information of the destination. Convert to a wear address and transfer the frame.

As described above, the address (hardware address) of the transmission source station used in the lower protocol in the frame is converted into the address of the relay device when being relayed by the relay device, so that this frame is received. The concentrator thus collected collects the address of the relay device. Even if the management station refers to this, it cannot recognize the transmission source station connected via this relay device.

Further, in the above-mentioned communication operation confirmation function,
If the concentrator to which the management station is connected and the station are connected via a relay device such as a router or bridge and the station is in a different network segment from the network segment to which the management station belongs, the management station Even if a frame for confirming communication operation is transmitted to the station, the response is not always obtained correctly. That is, depending on the transmission quality of the relay route between the management station and the station and the traffic load, the response itself may not be obtained, or the obtained response may be erroneous. The rate of correct response is determined by the transmission quality of the relay route and the traffic load. Therefore, the management station may not be able to confirm the station communication operation of another network segment. Also, it is not possible to know the transmission quality of the other network segment. Furthermore, depending on the route information set in the station (routing information; information about which relay device should be used), the station may not be able to send a response to the communication operation confirmation frame to the management station. is there. In such a case, the management station cannot know the communication operation status of the station.

Further, in order for the concentrator to collect and retain the information of the transmission source station from the last received frame, the concentrator must perform an operation of updating the information of the transmission source station every time the frame is received. become. When the traffic of frames flowing through the network increases, the processing load for the update operation increases, which may lead to problems such as dropping frames.

Therefore, an object of the present invention is to solve the above problems and to provide a concentrator with a network management function that can properly collect information even when there is a station via a relay device.

[0012]

In order to achieve the above object, the present invention holds, for each input port, an address used by a higher-level protocol of a source station in a frame last received by the input port, It has a function of transmitting the held address to the management station in response to a request from the management station.

Alternatively, a frame for communication operation confirmation is transmitted to the station designated by the management station the number of times designated by the management station, and the response result from the designated station for this frame is held, and the response result is held. Is transmitted to the management station in response to a request from the management station.

Further, for each input port, the source IP address in the last received IP frame and ARP frame of the input port is held, and the held IP address is transmitted to the management station in response to a request from the management station. It has a function.

[0015]

[Operation] Station is a lower address (hardware address)
And a higher address (software address; IP address). In the frame transmitted by the station, both the lower address and the higher address of the source station are included. This upper address is not rewritten even through the relay device. With the above configuration, the concentrator with the network management function holds the address (IP address) used by the higher level protocol of the transmission source station in the frame received last by each input port. Even if the frame source station is connected to the input port via the relay device, the address used by the higher level protocol of the source station in the frame is not rewritten in the relay device, so the network management function is added. The address held by the concentrator correctly represents the source station.

Further, the network management function-equipped concentrator transmits a frame for communication operation confirmation to the station designated by the management station the number of times designated by the management station. When the station receives this frame, it responds to it. In order for the traffic load on the network segment in which the station exists to be large, the station may not receive this frame or the response may not arrive at the concentrator with the network management function. I get a response in time. The network concentrator with network management function holds the response result and transmits the response result to the management station in response to a request from the management station.

When the IP router is used as the relay device, when transferring the IP frame, the IP router sends the IP address of the source station as it is to the concentrator, and the concentrator holds it. The supervising station can collect information on the source station. On the other hand, the ARP frame transmitted by the source station is not transferred by the IP router, and the concentrator receives the AR transmitted by the IP router.
Only P frames arrive. Since the transmission source IP address in this ARP frame is the IP address of the IP router, the concentrator holds this, so that the supervision station can collect the information of the IP router.

[0018]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In the following description, SNMP (Simple
Network Management Protocol, IP (Internet Protoc)
ol), ICMP (Internet Control Message Protoco
Protocols such as l) and ARP (Address Resolition Protocol) are widely known protocols that belong to the Internet. The communication frame in the SNMP, IP, and ICMP protocols has the structure shown in FIG. 5 and includes a MAC header and an IP header. Also, the communication frame in the ARP protocol has the structure shown in FIG. The concentrators with network management function used in the embodiments of the present invention are all concentrators capable of performing operations based on the Internet, and have a network management function conforming to SNMP.

First, a first embodiment of the present invention will be described.

In the network shown in FIG. 1, a concentrator with a network management function (hereinafter referred to as a concentrator)
The management station 101 and the router 103 are connected to the port 102. A network segment 201 and another network segment 202 with this router 103 as a boundary
Will be called separately. Network segment 20
In 2 there is a station 104. The concentrator 102 has a SNMP communication function for returning a response to an inquiry about a management parameter from the management station 101 and setting a management parameter that can be set in response to a setting request from the management station 101.

Whenever the frame transmitted by the station 104 arrives, the concentrator 102 holds in the concentrator 102 the IP address of the transmission source station written in the IP header of this frame. At this time, the router 103 relays this frame from the station 104 to the concentrator 102 without rewriting the IP address of the transmission source in the frame, so that the concentrator 102 transmits the frame to the station 1 which is the transmission source station.
The IP address of 04 will be held. In this way, the IP address of the transmission source station of the last arrived frame is always held in the concentrator 102.

The management station 101 specifies the input port to the concentrator 102 connected to the network 202, and requests the IP address number of the transmission source station of the frame last received by the input port.

When the frame arrives at the designated input port, the concentrator 102 immediately sends the management station 101 the IP address of the source station (here, the station 104) of the frame last received by the input port. To do. Therefore,
The management station 101 can collect information on the station 104.

Next, a second embodiment of the present invention will be described.

In the present embodiment, there is a similar concentrator 105 in the network segment 202 for the network of FIG. 1, and the router 103 and the station 104 are connected to the port of the concentrator 105. Here, for the sake of distinction, two concentrators are designated as a concentrator A102 and a concentrator B1.
05.

Each concentrator returns a response to an inquiry about a management parameter from a remote management station, and an SNMP communication function for setting a management parameter that can be set in response to a setting request from the remote management station. I, which is a frame for inquiring a communication operation used in IP.
It has a function to send an echo request (Echo-Request) frame of CMP and receive an echo reply (Echo-Repry) which is a response to the echo request. The number of continuous transmissions and the transmission result (whether there is a response from the transmitting station and the time until the response is received) are held as management parameters that can be acquired and set by SNMP.

Of the concentrators connected to the network, the management station 101 is a concentrator that belongs to the network segment whose communication status is to be known (concentrator B10 in this case).
For 5), the number of continuous transmissions and the IP address of the station (station 104) that is the destination of the echo request are specified using the SNMP communication function. It is assumed that the station 104 cannot communicate via the router 103 because the relay route settings are different.

When the designated continuous transmission count is 1 or more,
The concentrator B105 immediately transmits the echo request to the station 104 a specified number of times. The station 104 uses the concentrator B1 in the network segment 202 with the same inquiry source.
Since it is 05, an echo reply can be transmitted. The concentrator B105 holds the result of this response.
Later, the management station 101 refers to this result by using the communication function of SNMP.

When the concentrator A 102 transmits the echo request to the station 104 a specified number of times, the station 1
Since 04 cannot communicate via the router 103, no response can be obtained from the line concentrator A102. Since the concentrator A102 does not respond to the specified number of inquiries even once, it is understood that the station 104 cannot directly communicate with the management station 101.

Next, a third embodiment of the present invention will be described.

In order for the management station 101 to recognize the IP address of the station connected to each port of the concentrator 102, the concentrator 102 holds the source IP address of the IP frame last arrived at each input port, The management station 101 stores the IP address held in response to the request from the management station 101.
When it comes to sending to, the following problems occur.

That is, when an IP router is connected to the port of the concentrator as a relay device, the IP frame arriving at that port is the one transmitted from the IP router itself and another IP frame relayed by the IP router. Some are transmitted from the transmitting station. If the IP frame arriving at the port is transmitted from another IP transmitting station relayed by the IP router, the IP address field of this IP frame is not the IP address of the IP router,
The IP address of the source station is set. For this reason,
Even if the concentrator wants to recognize the IP router connected to the port, it erroneously holds the IP address of the relayed source station, not the IP router connected to the port, and the remote management station 101 The wrong connected station may be recognized.

In order to solve this problem and the problem of an increase in processing load due to the increase in traffic, in the third embodiment, instead of an IP frame, the frequency of transmission is lower than that of an IP frame, and Use ARP frames that are not relayed by the router. The ARP is used to start communication between stations, and the ARP frame includes the IP address of the transmission source as shown in FIG.

The concentrator 102 holds, for each input port, the source IP address number in the IP frame and ARP frame last received by the input port, and holds the I
It has a function of transmitting the P address to the management station in response to a request from the management station.

In FIG. 3, the concentrator 102 is the station A10.
6 and the ARP frame transmitted by the IP router 103 arrive, the source IP address in this frame is held. In the ARP frame transmitted by the IP router 103,
Since the IP address of the IP router 103 is written as the source IP address, the IP address of the IP router 103 is collected in the concentrator 102. Since the ARP frame is transmitted from each station only once or twice immediately before the IP communication between the two stations is started,
The processing load is reduced as compared with the case where the source IP address is held from all the IP frames.

When the station B 104 existing in the network segment 202 performs IP communication with a station such as the station A 106 in the same network segment 201 as the concentrator 102, the ARP frame transmitted by the station B 104 is an IP router. Not relayed by 103. Therefore,
The concentrator 102 does not erroneously hold the IP address of the station B 104 as the IP address of the IP router 103. The IP frame transmitted by the station B 104 is relayed by the IP router 103, and the IP address of the station B 104 is written as the source IP address in the IP frame.
Addresses are collected.

In each embodiment, the network management function-equipped concentrator operates on the basis of the Internet, but the present invention can be applied to other networks having a hierarchical structure similar to the OSI reference model. Has the intended effect.

[0039]

The present invention exhibits the following excellent effects.

(1) Information on a remote station via the relay device can be correctly collected.

(2) The remote management station can collect the transmission quality / communication status in different network segments.

(3) The remote management station can obtain the communication operation status of the stations in different network segments that cannot communicate directly.

(4) Station information can be collected without being affected by an increase in traffic.

(5) The information of the IP router can be correctly collected even at the port to which the IP router is connected.

[Brief description of drawings]

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

FIG. 2 is a network configuration diagram showing an embodiment of the present invention.

FIG. 3 is a network configuration diagram showing an embodiment of the present invention.

FIG. 4 is a hierarchical diagram showing a protocol configuration.

FIG. 5 is a configuration diagram of communication frames in SNMP, IP, and ICMP.

FIG. 6 is a configuration diagram of a communication frame in ARP.

[Explanation of symbols]

 101 management station 102, 105 concentrator 103 relay device (router, IP router) 104, 106 station

Claims (3)

[Claims] 1. In a concentrator which is connected to a network such as a LAN and has a plurality of input / output ports for connecting a management station, a relay device for connecting the stations, etc., each input port receives the last input port. A concentrator with a network management function, having a function of holding an address used in a higher-level protocol of a transmission source station in a frame and transmitting the held address to the management station in response to a request from the management station. 2. A concentrator connected to a network such as a LAN and having a plurality of input / output ports for connecting a management station, a relay device connecting the stations, etc., to a station designated by the management station. It has a function to send a frame for communication operation confirmation the number of times specified by, hold the response result from the designated station to this frame, and send this response result to the management station in response to a request from the management station. A concentrator with a network management function. 3. A concentrator connected to a network such as a LAN and having a plurality of input / output ports for connecting a management station, an IP router connecting the stations, etc., the input port receives the last input port for each input port. IP frame and A
A concentrator with a network management function, which has a function of holding a source IP address in an RP frame and transmitting the held IP address to a management station in response to a request from the management station.