CN114157587B - Network device and network configuration determination method - Google Patents

Abstract

The invention provides a network device for solving the blocking state of a redundant network. A first determination unit (105) determines a port in a blocked state based on the states of the ports of the switches acquired by the first acquisition unit (103). A second determination unit (106) determines the port in the forwarding state based on the state of each port of the plurality of switches acquired by the first acquisition unit (103). A third determination unit (107) determines, among the ports in the forwarding state determined by the second determination unit, ports that do not exist in the MAC address tables of the switches acquired by the second acquisition unit (104). A determination unit (108) determines that the port determined by the third determination unit (107) is connected to the port in the blocked state determined by the first determination unit (105).

Description

Network device and network configuration determination method

Technical Field

The present invention relates to a network device for determining the configuration of a switch connected to a network and a network configuration determination method.

Background technique

Network redundancy is widely used in building systems, factory systems, etc. (see Patent Document 1). Among them, it is important for system managers and network managers to know the redundant parts of the network in advance in order to prevent erroneous settings in network settings.

Prior art literature

Patent Literature

Patent Document 1: Japanese Patent No. 3635268

Summary of the invention

Problem that the invention aims to solve

However, the blocked ports of the redundant parts of the network can be identified by using SNMP. However, in SNMP, there is no definition of the destination port information of the blocked port. Therefore, in the conventional technology, it is considered difficult to determine the destination port of the blocked port. In the management of building systems, factory systems, etc., it is important to confirm the status of the network from the perspective of safety and fault analysis, and it is also required to grasp the actual status of information related to the blockage.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to be able to grasp the congestion state of a redundant network.

Technical means of solving problems

The network device of the present invention comprises: a search unit configured to send a request for searching a device connected to a network, wherein the network is connected to a switch having a port in a blocked state, and wherein the search unit registers a MAC address of the device to each of a plurality of switches connected to the network; an instruction unit configured to send an instruction to each of a plurality of switches after the search unit sends a request, wherein the instruction is to send a request message for requesting a return by setting an IP address that does not exist on the network as a sending source to each of the plurality of switches; a first acquisition unit configured to acquire port status information from each of the plurality of switches via the network after the instruction unit sends the instruction; a second acquisition unit configured to acquire a MAC address table from each of the plurality of switches via the network after the instruction unit sends the instruction; a first determination unit configured to determine a port in a blocked state according to the states of the ports of each of the plurality of switches obtained by the first acquisition unit; a second determination unit configured to determine a port in a forwarding state according to the states of the ports of each of the plurality of switches obtained by the first acquisition unit; and a third determination unit configured to determine, among the ports in the forwarding state determined by the second determination unit, A method for determining a port that does not exist in the MAC address table of each of the plurality of switches acquired by the second acquisition unit; and a determination unit configured to determine that the port determined by the third determination unit is connected to the port in the blocked state determined by the first determination unit.

In one configuration example of the above-mentioned network device, the request sent by the search unit is an ARP request or an IPv6 multicast listener query (Multicast Listener Query).

In one configuration example of the above-mentioned network device, a plurality of switches are connected via the SNMP protocol.

The network configuration determination method of the present invention comprises: a first step of sending a request for searching a device connected to a network, wherein the network is connected to a switch having a port in a blocking state, and registering a MAC address of the device to each of a plurality of switches connected to the network; a second step of sending an instruction to each of a plurality of switches after sending the request in the first step, wherein the instruction is to send a request message for requesting a return by setting an IP address that does not exist on the network as a sending source to each of the plurality of switches; a third step of obtaining port status information from each of the plurality of switches via the network after sending the instruction in the second step; a fourth step of obtaining a MAC address table from each of the plurality of switches via the network after sending the instruction in the second step; a fifth step of determining a port in a blocking state according to the status of each port of the plurality of switches obtained in the third step; a sixth step of determining a port in a forwarding state according to the status of each port of the plurality of switches obtained in the third step; and a seventh step of determining, among the ports in the forwarding state determined in the sixth step, a port that does not exist in the MAC address table of each of the plurality of switches obtained in the fourth step. and an eighth step, which determines that the port in the blocked state determined in the fifth step is connected to the port determined in the seventh step.

In one configuration example of the above-mentioned network configuration determination method, the first step is to search for a switch connected to the network and send a request to the searched switch.

In one configuration example of the above-mentioned network configuration determination method, the request sent in the first step is an ARP request or an IPv6 multicast snooping query.

In one configuration example of the above-mentioned network configuration determination method, a plurality of switches are connected via the SNMP protocol.

Effects of the Invention

As described above, according to the present invention, ports not included in the MAC address tables of the respective switches are identified among the ports in the forwarding state, so that the ports of the switches connected to the ports in the blocked state can be determined, and the blocked state of the redundant network can be understood.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the configuration of a network device 100 according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a network configuration determination method according to an embodiment of the present invention.

FIG. 3 is a block diagram showing the hardware configuration of network device 100 according to the embodiment.

Detailed ways

1 , a network device 100 according to an embodiment of the present invention is described. The network device 100 includes a search unit 101, an instruction unit 102, a first acquisition unit 103, a second acquisition unit 104, a first determination unit 105, a second determination unit 106, a third determination unit 107, a determination unit 108, a display unit 109, an input unit 110, and a connection unit 112.

The search unit 101 sends a request to search for a device connected to the redundant network 120, and registers the MAC address of the device connected to the network 120 in a switch connected to the network 120. One of the plurality of switches connected to the network 120 has a port in a blocked state.

For example, by sending out an ARP (Address Resolution Protocol) polling scan, etc., IPv4 devices connected to the network 120 are searched, and as a result, the MAC addresses of these IPv4 devices are registered in the switch connected to the network 120. In addition, by sending out an MLQ (Multicast Listener Query), IPv6 devices connected to the network 120 are searched, and as a result, the MAC addresses of these IPv6 devices are registered in the switch connected to the network 120.

The network device 100 is connected to a network 120 via a connection unit 112 having a network connection function. To the network 120, for example, a management server constituting a building management system, a monitoring server, terminal devices, and the like are connected.

In the example shown in FIG1 , a switch A131, a switch B132, and a switch C133 are connected to the network 120. In this example, a switch B132 and a switch C133 are connected to one of the multiple ports of the switch A131 via a predetermined LAN cable. In addition, for redundancy, a blocking port 132a of the switch B132 and a forwarding port 133a of the switch C133 are connected via a predetermined LAN cable.

After the search unit 101 sends the above request, the command unit 102 sends (sends) a command to each of the multiple switches, and the command is to send a request message (for example, Ping) requesting a return by setting an IP address (virtual address) that does not exist on the network 120 as the sending source. Each switch that receives the Ping broadcasts the ARP request for the virtual address, and thus registers the MAC address of the switch other than itself (the switch) in the MAC address table of all switches.

After the instruction unit 102 sends the instruction, the first acquisition unit 103 acquires the information of the port status from each of the plurality of switches via the network. For example, if the plurality of switches are connected via the SNMP (Simple Network Management Protocol), the port status can be acquired from each switch via "OID: 1.3.6.1.2.1.17.2.15.1.3" using the SNMP protocol.

After the instruction unit 102 sends the instruction, the second acquisition unit 104 acquires the MAC address table from each of the plurality of switches via the network. This acquisition is performed before the MAC address table of the switch is updated. The MAC address table is acquired together with the identification information of the corresponding switch. For example, the second acquisition unit 104 can acquire the MAC address table from each of the plurality of switches through "OID: 1.3.6.1.2.1.17.4.3.1.2" using the SNMP protocol. In addition, the IP address set in the target switch is known in advance.

The first determination unit 105 determines a port in a blocking state based on the states of the ports of the plurality of switches acquired by the first acquisition unit 103. There is only one blocked port in the entire redundant network. The second determination unit 106 determines a port in a forwarding state based on the states of the ports of the plurality of switches acquired by the first acquisition unit 103.

The third determination unit 107 determines a port that does not exist in the MAC address table of each of the plurality of switches acquired by the second acquisition unit 104, among the ports in the forwarding state determined by the second determination unit 106. The determination unit 108 determines that the port determined by the third determination unit 107 is connected to the port in the blocking state determined by the first determination unit 105. The determination unit 108 displays the determined connection state on the display unit 109.

Normally, if a switch or device is connected, if it is a port in forwarding state, the port information will be in the MAC address table. However, in a redundant configuration, in a port connected to a blocked port, data packets do not flow, MAC address learning is not performed, and port information is not registered in the MAC address table, so it can be determined that the port is connected to a blocked port.

In addition, network device 100 starts the operations of search unit 101 , instruction unit 102 , first acquisition unit 103 , second acquisition unit 104 , first determination unit 105 , second determination unit 106 , third determination unit 107 , and determination unit 108 , for example, based on an instruction input from input unit 110 .

Next, the operation of network device 100 (network configuration determination method) according to the embodiment will be described with reference to the flowchart of FIG. 2 .

First, in the first step S101, the search unit 101 sends a request to search for a device connected to the network 120, to which a switch having a port in a blocked state is connected. As a result of searching for a device by sending the request, the MAC address of the device connected to the network 120 is registered in the switch connected to the network. As described above, one of the plurality of switches has a port in a blocked state.

After the search unit 101 sends the request, in the second step S102, the instruction unit 102 sends an instruction to each of the multiple switches, and the instruction is to send a request message (for example, Ping) requesting a return by setting an IP address that does not exist on the network 120 as the sending source to each of the multiple switches.

Next, in the third step S103, after the instruction unit 102 sends the instruction in the second step S102, the first acquisition unit 103 acquires the information of the port status from each of the plurality of switches via the network. Next, in the fourth step S104, the second acquisition unit 104 acquires the MAC address table from each of the plurality of switches via the network 120.

Next, in the fifth step S105, the first determination unit 105 determines a port in a blocking state according to the states of the ports of the plurality of switches acquired by the first acquisition unit 103 in the third step S103. In addition, in the sixth step S106, the second determination unit 106 determines a port in a forwarding state according to the states of the ports of the plurality of switches acquired by the first acquisition unit 103 in the third step S103.

Next, in the seventh step S107 , the third determination unit 107 determines, among the ports in the forwarding state determined by the second determination unit 106 in the sixth step S106 , ports that do not exist in the MAC address tables of the plurality of switches acquired by the second acquisition unit 104 in the fourth step S104 .

Next, in the eighth step S108, the determination unit 108 determines that the port determined by the third determination unit 107 in the seventh step S107 is connected to the port in the blocked state determined by the first determination unit 105 in the fifth step S105. Thereafter, in the ninth step S109, the connection state determined by the determination unit 108 is displayed on the display unit 109.

Through the above-described processing, in the example shown in FIG. 1 , it is determined that the forwarding port 133 a of the switch C 133 is connected to the blocking port 132 a of the switch B 132 , and the connection information is displayed on the display unit 109 .

In addition, as shown in FIG3 , the network device 100 of the above embodiment may also be a computer device having a CPU (Central Processing Unit) 301, a main storage device 302, an external storage device 303, and a network connection device 304, etc. The CPU 301 operates (executes the program) according to the program expanded in the main storage device 302, thereby realizing the above functions (network configuration determination method). The above program is a program for a computer to execute the network configuration determination method shown in the above embodiment. The network connection device 304 is connected to a network 305. In addition, each function may also be distributed to a plurality of computer devices.

As described above, according to the present invention, among the ports in the forwarding state, ports that do not exist in the MAC address tables of the plurality of switches are identified, so that the ports of the switches connected to the ports in the blocking state can be determined, and the blocking state of the redundant network can be understood.

In addition, the present invention is not limited to the above-described embodiments, and it is obvious that a person having ordinary knowledge in the art can implement various modifications and combinations within the technical concept of the present invention.

Symbol Description

100…network device, 101…search unit, 102…instruction unit, 103…first acquisition unit, 104…second acquisition unit, 105…first determination unit, 106…second determination unit, 107…third determination unit, 108…judgment unit, 109…display unit, 110…input unit, 112…connection unit, 120…network, 131…switch A, 132…switch B, 132a…blocking port, 133…switch C, 133a…forwarding port.

Claims (6)

1. A network device, characterized by having: a search unit configured to send a request for searching for a device connected to a network to which a switch having a port in a blocked state is connected, and to register a MAC address of the device in each of a plurality of switches connected to the network; an instruction unit configured to send an instruction to each of the plurality of switches after the search unit sends the request, wherein the instruction is to send a request message for requesting a return by setting an IP address that does not exist on the network as a sending source to each of the plurality of switches, and the plurality of switches that receive the request message broadcast an ARP request for a virtual address and register the MAC addresses of switches other than the switch itself in the MAC address tables of all switches; a first acquisition unit configured to acquire port status information from each of the plurality of switches via the network after the instruction unit sends the instruction; a second acquisition unit configured to acquire a MAC address table from each of the plurality of switches via the network after the instruction unit sends the instruction; a first determination unit configured to determine a port in a blocked state based on the states of the ports of each of the plurality of switches acquired by the first acquisition unit; a second determination unit configured to determine a port in a forwarding state according to states of the ports of each of the plurality of switches acquired by the first acquisition unit; a third determination unit configured to determine, among the ports in the forwarding state determined by the second determination unit, ports that do not exist in the MAC address table of each of the plurality of switches acquired by the second acquisition unit; and The determination unit is configured such that the port determined by the third determination unit is connected to the port in the blocked state determined by the first determination unit. 2. The network device according to claim 1, characterized in that: The request sent by the search unit is an ARP request or an IPv6 multicast snooping query. 3. The network device according to claim 1 or 2, characterized in that: The multiple switches are connected via SNMP protocol. 4. A network composition determination method, characterized by: A first step is to send a request to search for a device connected to a network, the network being connected to a switch having a port in a blocked state, and registering a MAC address of the device to each of a plurality of switches connected to the network; The second step is to send an instruction to each of the plurality of switches after sending the request in the first step, wherein the instruction is to send a request message to each of the plurality of switches, in which an IP address not existing on the network is set as a sending source, and to request a return, and the plurality of switches receiving the request message broadcast an ARP request of a virtual address, and register the MAC addresses of switches other than the switch in the MAC address tables of all switches; A third step, after sending the instruction in the second step, obtaining port status information from each of the plurality of switches via the network; A fourth step, after sending the instruction in the second step, obtaining a MAC address table from each of the plurality of switches via the network; The fifth step is to determine the ports in the blocking state according to the states of the ports of the plurality of switches respectively acquired in the third step; The sixth step is to determine a port in a forwarding state according to the states of the ports of the plurality of switches respectively obtained in the third step; In a seventh step, among the ports in the forwarding state determined in the sixth step, a port that does not exist in the MAC address table of each of the plurality of switches obtained in the fourth step is determined; and In an eighth step, it is determined that the port determined in the seventh step is connected to the port in the blocked state determined in the fifth step. 5. The network composition determination method according to claim 4, characterized in that: The request sent in the first step is an ARP request or an IPv6 multicast snooping query. 6. The network configuration determination method according to claim 4 or 5, characterized in that: The multiple switches are connected via SNMP protocol.