JP2002344510A - Network management system, device and method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system in which a node in an overload state is not subjected to congestion control to avoid a reduction in performance of a network. SOLUTION: An SNMP manager 10 collects periodically or immediately the load state of an SNMP agent to be managed which is connected via a network, and examines whether or not the load state corresponds to a load level preset. When a magnitude predetermined in the load level has changed, the SNMP manager 10 requests to change a flow pattern to be filtered to a preset node of a notice destination.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network management technique, and more particularly, to a method and system suitable for network management that avoids a decrease in network performance when an overloaded node or the like exists. , And the program.

[0002]

[Prior Art] SNMP (Simple Network Management P)
rotocol), for example, fault management, configuration management, performance
Management items such as maintenance management, security management, and billing management are managed by the SNMP manager (management station) installed in the management system and the network devices to be managed.
It is divided into SNMP agent nodes, and the interval between them is managed using the SNMP protocol. Between the SNMP manager and the SNMP agent, the manager uses the MIB (Managed Information Base) based on a management database item. Information is acquired and set by a process such as Get (Get) and Set (Set) to the agent, and a trap of an event notification is transmitted when a failure occurs on the agent side. The SNMP protocol is
A simple protocol for the agent to respond to a request from the manager. For example, GetRequest (information collection request), GetResponnse (information collection response), SetRequest (information content change request), Trap
A request and a response (response) are performed between the management station and the agent by using a PDU (Protocol Data Unit) called (event notification).

[0003] For example, Japanese Patent Application Laid-Open No. H11-313064 discloses that trap information is received from a plurality of managed devices (SNMP agents), and the managed device is provided with a trap information corresponding to the amount of failure notification of the received trap information. To change the filtering conditions for the received trap information,
There has been proposed a network management device that can recognize the discard of trap information according to the load level corresponding to the failure notification amount for each managed device.

[0004] In a network system, when a congested node itself performs flow control, there is a case where the processing performance of the node cannot be exhibited due to the flow control itself.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a system, a method, and a program for reducing the load on an overloaded network node and avoiding a decrease in network performance. Is to do.

[0006]

According to one aspect of the present invention, which provides means for solving the above-mentioned problems, a management device for managing a plurality of managed devices connected via a network is provided. Means for collecting the load statuses of a plurality of managed devices, and wherein the collected load statuses of the managed devices are pre-registered corresponding to the overloaded managed devices when the load status is an overload level. Means for transmitting a request to change a flow pattern for performing a packet filtering process to the managed device of the notification destination, comprising: transmitting a request from the managed device of the notification destination to the managed device in the overloaded state. It is configured to filter specific packets.

[0007] In the present invention, the management apparatus may set the collected load status of the managed device to a predetermined value.
Or, check whether the load level of the plurality of stages corresponds to a predetermined overload level, and if the load state of the managed device is overloaded, register in advance corresponding to the managed device in the overloaded state. Notifying the managed device of the notification destination that is being notified of the identification information and the load level of the managed device in the overloaded state, and requesting to change the filtering state of the packet, from the management device The managed device of the notification destination that has received the filtering state change request determines a flow to be filtered based on the notified identification information and the load level of the managed device in the overloaded state, and the determined flow is determined. Based on the flow, the packets to the overloaded managed device are filtered. In the present invention, the management device checks whether the collected load status of the managed device is equivalent to a preset load level, and determines that the collected load status of the managed device is the load collected last time. In the case where the load level has changed, the load level of the managed device and the identification information of the managed device are notified as overload notifications by a notification destination registered in advance corresponding to the managed device whose load level has changed. To the managed device. It is immediately apparent from the description of the following embodiments that the above-mentioned problems can be similarly solved by the inventions described in the claims.

[0008]

Embodiments of the present invention will be described. In one embodiment of the present invention, the management manager periodically or immediately collects the load status of a managed node connected via a network, and the load status corresponds to a preset load level. Request to change the flow pattern for filtering to a preset notification destination node when there is a change in the load level by a predetermined amount. Things.

In one embodiment of the present invention, a management device (10 in FIG. 1) for performing network management includes means for collecting the load status of a plurality of managed devices connected via a network, Check whether the load state of the management device corresponds to a preset load level,
If the load state of the managed device collected this time has changed by a predetermined amount or more from the load state of the managed device collected last time, the notification destination set in advance to the management device is changed. Means are provided for requesting the managed device to change the flow pattern for performing filtering. In one embodiment of the present invention, the managed device at the notification destination, which has received the request to change the flow pattern for performing filtering from the management device (10 in FIG. 1), changes the flow pattern for performing packet filtering, Filtering packets to the overloaded managed device. That is, the managed device at the notification destination filters the packet to the overloaded managed device, and the packet is not transmitted to the overloaded managed device.

In one embodiment of the present invention, the above-described units and processes in the management device and the managed device are executed by CPUs constituting the management device and the managed device, respectively. Is achieved.

In one embodiment of the present invention, the management device (10), for each managed device, determines from the identification information of the managed device, the load information, and the identification information of the managed device adjacent to the managed device. CPU load information management data (101 in FIG. 3) including the following information and load level management data (102 in FIG. 3) for storing the correspondence between the load level and the load information are stored in the storage unit.

[0012] In one embodiment of the present invention, the managed device stores the identification number and load level of the adjacent managed device as a flow pattern list to be filtered when the managed device adjacent to the managed device is overloaded. And the flow to be filtered is stored in the storage unit as one entry.

When the load state of the managed device changes to the overload level, the management device sends a notification to the managed device of the notification destination registered in advance corresponding to the managed device in the overloaded state. The identification information and the load level of the managed device in the overloaded state are notified, and a request is made to change a flow pattern for performing a packet filtering process. Based on the notified identification information and the load level of the overloaded managed device, determine a flow to be filtered, and, based on the determined flow, send a packet to the overloaded managed device. Filter.

[0014] In one embodiment of the present invention, the management device (10) is adjacent to the managed device when the collected load level of the managed device has changed from the previously collected load level. A request to change the flow pattern for filtering is transmitted to the managed device. Alternatively, when the load level of the collected managed device has changed from the previously collected load level, the management device (10) may change, among the managed devices connected to the management device, the changed managed device. A request to change the flow pattern to be filtered is transmitted to the managed devices other than the management device.

An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing an example of the configuration of the embodiment of the present invention. FIG. 2 is a diagram showing an example of CPU load information management data (101) stored and held by an SNMP manager as a management device. In the present invention, a management station (“SNMP
Manager) 10 and managed devices (called SNMP agents) 1 running on the network,
SNMP (SimpleNe) as a protocol between 2, 3 and 4
The load status of each SNMP agent (target is an IP node) is collected periodically or immediately using twork Management Protocol). The SNMP manager (10) collects the collected SNMP
Check the load level of the agent to find out which load level corresponds to the preset load level, and if the load level of the SNMP agent collected this time has changed from the previous load level To the SNMP
The SNMP agent (adjacent agent) to be notified when the load level is changed is set in advance in the CPU load information management data 101 (see FIG. 2) stored and held in the manager (10). Request to change the flow pattern to perform the filtering.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, in order to describe the above-mentioned embodiment in more detail, an embodiment which is a specific example of the present invention will be described with reference to the drawings. FIG. 4 is a diagram for explaining the operation principle of one embodiment of the present invention. In the example shown in FIG. 4, four SNMP agents (1), (2), (3), (4)
Has a network configuration in which an SNMP manager 10 for managing the network exists. Each SNMP agent functions as a relay node (for example, a network device such as a router, a hub, or a repeater) for interconnecting networks.

<SNMP Manager 10> SNMP Manager 1
Reference numeral 0 denotes a network management device that manages an SNMP agent (1), an SNMP agent (2), an SNMP agent (3), and an SNMP agent (4) that constitute a system to be managed (managed device).

The SNMP manager 10 periodically sends each SNMP
Collect CPU load information from agents. The SNMP manager 10 sends a CPU load information acquisition request (request) to the SNMP agent, and the SNMP agent returns the load information (CPU usage rate) as a response (response).
Send to NMP manager 10. SNMP manager 10
If the load status of the SNMP agent changes,
SN adjacent to the SNMP agent whose load status has changed
Requests the MP agent to change the filtering status of IP packets.

<SNMP Agent (1)> The SNMP agent (1) is a node that relays the network A (10.1.0.0), the SNMP agent (2), and the SNMP agent (4).

The SNMP agent (1) responds to a CPU load information read request from the SNMP manager 10.

The SNMP agent (1) performs a filtering process in response to a filtering state change request from the SNMP manager 10 according to a preset flow pattern.

<SNMP Agent (2)> The SNMP agent (2) relays the network B (10.2.0.0), the network C (10.3.0.0), the SNMP agent (1), and the SNMP agent (3). Node.

The SNMP agent (2) responds to a CPU load information read request from the SNMP manager 10.

The SNMP agent (2) performs a filtering process in response to a filtering state change request from the SNMP manager 10 according to a preset flow pattern.

<SNMP Agent (3)> The SNMP agent (3) includes the network D (10.4.0.0) and the network E
(10.5.0.0) and SNMP agent (2), SNMP agent
This is the node that relays (4).

The SNMP agent (3) responds to the CPU load information read request from the SNMP manager 10.

The SNMP agent (3) performs a filtering process in response to a filtering state change request from the SNMP manager 10 according to a preset flow pattern.

<SNMP Agent (4)> The SNMP agent (4) is a node that relays the network F (10.6.0.0) to the SNMP agent (1) and the SNMP agent (3).

The SNMP agent (4) responds to the CPU load information read request from the SNMP manager 10.

The SNMP agent (4) performs a filtering process in response to a filtering state change request from the SNMP manager 10 according to a preset flow pattern.

The operation of the embodiment of the present invention will be described. The information that needs to be set in advance by the maintenance person is as follows. That is, the setting of the adjacent SNMP agent,
This is the setting of the load level management data and the setting of the flow pattern to be filtered.

1. <Setting of adjacent SNMP agent> When the SNMP agent is overloaded, select a node to filter IP packets. The setting target is the CPU load information management data 1 of the SNMP manager 10.
01. As schematically shown in FIG. 3, adjacent agent numbers are set for each agent number.

2. <Setting of load level management data> Set the CPU usage rate to start filtering. If the filtering range is divided into a plurality of ranges depending on the degree of load, the number of levels is set. The setting target is the load level management data 102 of the SNMP manager 10, and FIG.
The load information corresponding to the overload level (CPU
Is set.

FIG. 5 shows an embodiment of the SNMP according to the present invention.
FIG. 3 is a diagram schematically illustrating an example of CPU load information management data 101 and load level management data 102 of a manager 10, and a sequence of a request (CPU load information read request) from the SNMP manager 10 and a response of an SNMP agent. In the example illustrated in FIG. 5, two levels of overload levels (overload level 1 and overload level 2) are set in the load level management data 102 set in the SNMP manager 10.

3. <Setting of Filtering Target Flow Pattern> For each adjacent SNMP agent, a list of flow patterns to be filtered when the adjacent SNMP agent is overloaded is registered. The setting target is all SNMP
Agent. The SNMP agent stores and holds setting information including an agent number, a load level, and a flow to be filtered as one entry.

As shown in FIG. 3, the SNMP agent (1)
In the above, the list of flow patterns to be filtered when the agent adjacent to the SNMP agent (1) (agents (2) and (4)) is overloaded is as follows: When agent number 2 is at load level 1, the flow to be filtered is a flow A, when the agent number 2 is at the load level 2, the flows to be filtered are the flows B and C. When the agent number 4 is at the load level 1, the flows to be filtered are the flow D. In the case of, the flow to be filtered is set to flow E.

In the SNMP agent (4), the list of flow patterns to be filtered when the adjacent agents (agents (1) and (3)) are overloaded is as follows: When the agent number 1 is at the load level 1, the flow to be filtered is Is the flow F, • When agent number 1 is at load level 2, the flow to be filtered is flow G. • When agent number 3 is at load level 1, the flow to be filtered is flow D. • Agent number 3 is at load level 2. In the case of, the flow to be filtered is set to flow E. A specific example of each flow will be described later with reference to FIG.

FIG. 6 shows an example of the SN according to the embodiment of the present invention.
An example of the CPU load information management data 101 of the MP manager, the load level management data 102, and a list of flow patterns to be filtered by each SNMP agent are shown.

In FIGS. 5 and 6, since the overload state is divided into two stages, the flow pattern is set for each level. However, a high-level flow pattern includes a flow pattern below that level. That is, the flow pattern set at the load level 2 is a flow pattern to be added to the flow pattern at the load level 1.

The flow pattern to be filtered is determined by an IP (Internet Protocol) as shown below.
ol) or a combination of flow elements included in the header information of TCP (Transport Control Protocol).

Source IP address Destination IP address Subnet mask Protocol type Port number TOS field (Example: Cisco router access list)

An example of a flow pattern used in one embodiment of the present invention (see FIG. 4) is shown in FIG. 10 as a list in a table format.

Next, the operation of the embodiment of the present invention will be described. FIG. 7 is a flowchart showing a processing procedure according to an embodiment of the present invention. First, the SNMP manager 10 periodically requests the CPU usage rate (Request in FIG. 5) from all the SNMP agents (1) to (4) (Step A).
1).

Next, each SNMP agent notifies the SNMP manager 10 of the requested CPU usage rate as a response (Response in FIG. 5).

The SNMP manager 10 converts the CPU load information collected from each SNMP agent into load level management data 102.
And (Step A2). The load level management data 102 managed by the SNMP manager 10 is stored in advance by the maintenance
It is set in the manager 10. When the load information (%) set for each overload level is equal to or more than the load information (%), it is determined that an overload state has occurred.

In the example shown in FIG. 5, the load level management data
As the setting contents of 102, the overload level 1 is the CPU load information.
(%) Is 80% or more, and overload level 2 is CPU load information (%)
Is 90% or more.

In the example shown in FIG. 5, the SNMP agent (1)
Indicates that the CPU load is 93% and the overload level is 2, and the SNMP agent (4) has a CPU load of 86% and corresponds to the load level 1.

When the load level of the collected SNMP agent has changed compared to the time when it was collected in the previous cycle (previous time) (YES in step A3), the SNMP manager 10 sends the SNMP agent whose load level has changed. To the adjacent SN registered in the CPU load information management data 101 in advance.
The load level and the SNMP agent number are notified to the MP agent (step A4 in FIG. 7). In this case, it is assumed that the load level in the previous cycle is level 1 or less for all SNMP agents.

The SNMP manager 10 is an SNMP agent
Neighbor SNMP agent (2) registered for (1),
Load level of SNMP agent (1) is "2" for (4)
Is notified (solid line in FIG. 6). The SNMP manager 10 sends an SNMP request to the adjacent SNMP agents (1) and (3) registered for the SNMP agent (4).
It notifies that the load level of the agent (4) has become "1" (broken line in FIG. 6).

The SNMP agent, which has been notified of the overload of the adjacent SNMP agent from the SNMP manager 10, responds to the notified SNMP agent number and load level according to the setting of the preset flow pattern list to be filtered. The flow to be filtered is determined, and the filtering process of the flow is started.

A description will be given of a flow pattern filtered by the overload state of the SNMP agent (1).

In the adjacent SNMP agents (2) and (4), according to the setting contents of the flow pattern list to be filtered, the flow to be filtered is set to the flow pattern (load level) corresponding to the agent number 1 and the load level “2”.
The flow pattern set in "2" becomes a flow pattern to be added to the flow pattern of the load level "1"), and the IP packet to the SNMP agent (1) is filtered. Since the overload level of the load A is “2”, the flow A1 (load level)
1 ") and the flow pattern of the flow A2 (see FIG. 10), whereby the source port number" 80 "transmitted to the destination network A is transmitted.
And all the IP packets with the port number “21” are filtered.

The flow pattern filtered by the overload state of the SNMP agent (4) will be described. The adjacent SNMP agents (1) and (3) change the flow to be filtered to one corresponding to the agent number 4 and the load level 1, and filter the IP packet to the SNMP agent (4).

The overload level of the SNMP agent (4) is "
1 ", the flow pattern of the flow F1 (see FIG. 10) is filtered. As a result, all IP packets having the transmission source of the network B and the destination of the network F are filtered. SNMP agent, SN
The processing in each step of the MP manager shown in FIG.
The processing and functions are realized by a program executed by the CPU on the network node.

Next, another embodiment of the present invention will be described. FIGS. 5, 6, and 10 are diagrams for explaining the second embodiment of the present invention. In the second embodiment of the present invention, FIG. 5, FIG. 6, and FIG. 10 are changed to the contents of FIG. 8, FIG. 9, and FIG. 11 without changing the network configuration. It is.

As shown in FIG. 6, in the above embodiment, the SN
When the load level of the MP agent is changed, only the adjacent SNMP agent is notified. In this embodiment, however, the overload level of the SNMP agent is changed as shown in FIG. If changed
Notify all SNMP agents other than SNMP agent.

Further, in this embodiment, as shown in FIG. 8, the overload level managed by the load level management data 102 is only one stage.

The difference between FIG. 6 and FIG. 9 will be described. FIG.
As described above, in the above embodiment, the overload level is managed in two stages, but in this embodiment, as shown in FIG. 9, the overload level is managed in one stage.

Further, as shown in FIG. 6, in the above embodiment, when the SNMP agent is overloaded, the same flow pattern is filtered by the adjacent SNMP agent. In this embodiment, as shown in FIG. 9, a flow pattern for performing filtering differs depending on each SNMP agent (see FIG. 11).

The operation of the second embodiment of the present invention is the same as that of the above-described embodiment described with reference to the flowchart of FIG. The SNMP manager 10 periodically requests the CPU usage rate of all the SNMP agents (1) to (4) (Request in FIG. 8) (step A1). Next, each SNMP
The agent notifies the SNMP manager 10 of the requested CPU usage rate as a response (Response in FIG. 8).

The SNMP manager 10 converts the CPU load information collected from each SNMP agent into load level management data 102.
And (Step A2). The load level management data 102 managed by the SNMP manager 10 is stored in advance by the maintenance
It is set in the manager 10. In the second embodiment, as shown in FIG. 8, when the load information (80%) set to the one-stage overload level is equal to or more than the load information (80%), the overload state is determined. In the example shown in FIG. 8, the CPU load of the SNMP agent (2) is 99%, which corresponds to the overload level 1.

When the load level of the collected SNMP agent changes from the load level at the time of the previous cycle (previous time) (YES in step A3), the SNMP manager 1
0 indicates an SNMP agent (1) registered in the CPU load information management data 101 in advance for an SNMP agent (2) having a change in load level (change to an overload level);
(3), (4), that is, SNMP excluding SNMP agent (2)
The agent is notified of the load level and the SNMP agent number (step A4 in FIG. 7).

The SNMP manager 10 determines that the load state of the SNMP agent (2) collected in a later cycle is overload level 1.
(80%), other than SNMP Agent (2)
Notify SNMP agents (1), (3), and (4), and SNMP agents (1), (3), and (4) notify SNMP agent (2) that SNMP agent (2) performed when overloaded. Do not perform filtering processing for packets of

[0064]

As described above, according to the present invention,
Even when an overloaded node exists, the network performance can be kept high.

The reason for this is that, in the present invention, when there is an overloaded managed device (SNMP agent), the surrounding managed device (SNMP agent) sends the overloaded managed device (SNMP agent). This is because, by filtering specific IP packets to the managed device, an overloaded managed device (SNMP agent) does not need to perform congestion control by itself and can concentrate on switching processing. As a result, the performance of the entire network can be kept high.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating an embodiment of the present invention.

FIG. 3 is a diagram for explaining one embodiment of the present invention.

FIG. 4 is a diagram for explaining one embodiment of the present invention.

FIG. 5 is a diagram for explaining one embodiment of the present invention.

FIG. 6 is a diagram for explaining one embodiment of the present invention.

FIG. 7 is a flowchart for explaining an embodiment of the present invention.

FIG. 8 is a diagram for explaining a second embodiment of the present invention.

FIG. 9 is a diagram for explaining a second embodiment of the present invention.

FIG. 10 is a diagram showing a list of flows in one embodiment of the present invention.

FIG. 11 is a diagram showing a list of flows in the second embodiment of the present invention.

[Explanation of symbols]

 1, 2, 3, 4 SNMP agent 11, 21 MIB (Managed Information Base) 10 SNMP manager 101 CPU load information management data 102 Load level management data

Claims (22)

[Claims] 1. A management device for managing a plurality of managed devices connected via a network, means for collecting load statuses of the plurality of managed devices, and wherein the collected load statuses of the managed devices are determined in advance. When the set overload level is reached, a change of a flow pattern for performing a packet filtering process on a managed device of a notification destination registered in advance corresponding to the managed device in an overloaded state. Means for requesting, the received managed device receiving the request from the management device, the managed device of the notification destination changes a flow pattern for performing a packet filtering process, to the managed device in an overloaded state A network management system for filtering packets. 2. A management device for managing a plurality of managed devices connected via a network, wherein: a means for collecting a load status of the plurality of managed devices; Check whether the load level corresponds to an overload level among one or a plurality of load levels set in advance, and if the load state of the managed apparatus is overloaded, the managed apparatus in the overloaded state is Correspondingly, the managed device of the notification destination registered in advance is notified of the identification information of the managed device in an overloaded state and its load level, and changes the flow pattern for performing the packet filtering process. Means for requesting that the managed device receive the request from the management device, the managed device to be notified receives the identification information of the notified managed device in an overloaded state, and the load level thereof. A flow to be filtered is determined based on the determined flow, and based on the determined flow, a packet to the managed device in an overloaded state is filtered. 3. The management device checks whether the collected load status of the managed device corresponds to one or more preset load levels of the managed device. When the load level of the device changes from the load level of the managed device collected previously,
The identification information of the managed device whose load level has changed and the load level of the managed device are registered in advance in correspondence with the managed device whose load level has changed,
3. The network management system according to claim 1, wherein a notification is sent to the managed device to which the notification is sent. 4. The management device sets the identification information of the managed device, the load information of the managed device, and the identification information of the managed device adjacent to the managed device as one entry, and assigns the entry to the managed device. 2. The storage unit according to claim 1, wherein CPU load information management data and load level management data for storing a correspondence between the load level and the CPU load information are stored in the storage unit.
4. The network management system according to any one of claims 3 to 3. 5. The method according to claim 1, wherein the managed device includes, as a flow pattern list to be filtered when the managed device adjacent to the managed device is overloaded, an identification number of the adjacent managed device, a load level, and a filtering target. The network management system according to any one of claims 1 to 3, wherein a flow pattern list including flow pattern information composed of flows for each adjacent managed device is stored in a storage unit. 6. The management apparatus according to claim 1, wherein the collected load status of the managed device changes from a previously collected load status of the managed device by a predetermined amount or more. 3. The network management system according to claim 1, further comprising: transmitting a request to change a flow pattern to be filtered to a managed device adjacent to the managed device in which the managed device has changed. 4. . 7. The management device connected to the management device when the load status of the collected managed device has changed by a predetermined amount or more from the previously collected load status. The apparatus according to claim 1, further comprising: a unit that transmits a request to change a flow pattern for performing a filtering process to the managed device, excluding the managed device in which the load state has changed, among the devices. 3. The network management system according to 1 or 2. 8. The management device according to claim 1, wherein the management device is an SNMP (Simple Network).
k Management Protocol) manager, and the managed device is configured as an SNMP agent, and the management device and the managed device communicate with each other by the SNMP protocol via the network.
The network management system according to any one of claims 1 to 7, wherein: 9. A process in which a management device periodically or immediately collects the load status of a plurality of managed devices connected via a network, and wherein the management device determines an overload from the collected load status. When there is a managed device in a state, a step of notifying the managed devices around the managed device in an overloaded state of the fact, and the managed device receiving the notification from the management device includes: Changing the flow pattern of the packet filtering process and filtering a specific packet to the overloaded managed device to reduce the load on the overloaded managed device. And a network management method. 10. A process in which a management device collects load statuses of a plurality of managed devices connected via a network, wherein the management device sets the collected load statuses of the managed devices in advance. Checking which one of the load levels corresponds to one or a plurality of stages, and in the management device, the load level of the managed device collected this time has changed from the load level of the managed device collected previously. Transmitting a request for changing a flow pattern for performing a packet filtering process to a managed device of a notification destination registered in advance, corresponding to the managed device having a change in load level. And filtering a specific packet from the managed device of the notification destination receiving the request to the managed device in an overloaded state. And a network management method. 11. The management apparatus according to claim 1, wherein the management apparatus is configured to provide the identification information of the overloaded managed apparatus to a managed apparatus of a notification destination registered in advance corresponding to the overloaded managed apparatus. Notifying the load level and requesting that the filtering state of the packet be changed, and receiving a request to change the flow pattern for performing filtering from the management device, A flow to be filtered is determined based on the identification information and the load level of the managed device in an overloaded state notified from the device, and a packet to the managed device in an overloaded state is determined based on the determined flow. 11. The network management method according to claim 10, wherein filtering is performed. 12. The CPU load information, wherein the management device includes, as one entry, identification information of the managed device, load information, and identification information of the managed device adjacent to the managed device as an entry for each managed device. Management data, load level and CPU
11. The network management method according to claim 10, further comprising storing and maintaining load level management data for storing correspondence of the load information. 13. The managed device, as a list of flow patterns to be filtered when the managed device adjacent to the managed device is overloaded, includes an identification number of the adjacent managed device, a load level, and a flow to be filtered. 11. The network management method according to claim 10, wherein the flow pattern including the information is stored and held in association with an adjacent managed device. 14. The management apparatus changes the load state when the collected load state of the managed apparatus has changed from a previously collected load state of the managed apparatus by a predetermined amount or more. 11. The network management method according to claim 10, wherein a request to change a flow pattern to be filtered is transmitted to a managed device adjacent to the changed managed device. 15. The management device, when the load status of the managed device collected has changed by a predetermined amount or more from the load status of the managed device collected last time, A request for changing a flow pattern to be filtered is transmitted to the managed devices, excluding the managed devices whose load status has changed, among the connected managed devices. 10. The network management method according to item 10. 16. The method according to claim 16, wherein the management device and the managed device are SNs.
16. An MP (Simple Network Management Protocol) manager and an SNMP agent, wherein the management device and the managed device transmit and receive information via the network using an SNMP protocol. A network management system according to any one of the preceding claims. 17. A network management apparatus for managing a plurality of managed devices connected via a network, wherein: a means for collecting a load status of the plurality of managed devices; It is checked whether the load level corresponds to one or a plurality of preset load levels, and the collected load level of the managed device has changed from the previously collected load level of the managed device. In the case, in response to the managed device in which the load level has changed, means for requesting the managed device of the notification destination registered in advance to change the flow pattern to perform filtering, A network management device, comprising: 18. Identification information of a managed device, load information,
With the identification information of the managed device adjacent to the managed device as one entry, the CPU load information management data including the entry for each managed device, and the load level management data storing the correspondence between the load level and the CPU load information. The network management device according to claim 17, further comprising storage means for storing. 19. The managed device adjacent to the managed device when the collected load condition of the managed device has changed from the previously collected load condition of the managed device by a predetermined amount or more. A means for transmitting a request to change a flow pattern to be filtered to a managed device, excluding the changed managed device, among the managed devices connected to the management device, The network management device according to claim 17, wherein 20. A managed device connected to a management device via a network, wherein the management device collects load states of the plurality of managed devices connected via a network, and Check whether the load state of the managed device corresponds to a preset load level, and if the load level has changed from the previously collected load level of the managed device, the load level Notifying the managed device of the notification destination registered in advance corresponding to the changed managed device, the identification information of the managed device whose load level has changed and its load level are notified, and the The managed device receiving a request to change the filtering state, and receiving a request to change a flow pattern for performing filtering from the management device, Means for receiving the known identification information and the load level of the overloaded managed device, and determining a flow to be filtered based on the identification information and the load level of the overloaded managed device; and Means for filtering a packet to the overloaded managed device based on the performed flow. 21. A program executed by a computer constituting a network management device for managing a plurality of managed devices connected via a network, wherein the first program collects a load state of the managed device. Processing, a second process of checking whether the collected load status of the managed device corresponds to one or more preset load levels, and a process of determining whether the collected load level of the managed device is , If the load level of the managed device collected last time has changed,
A notification destination managed device registered in advance corresponding to the managed device whose load level has changed is notified of the identification information of the managed device whose load level has changed and its load level. And a third process for requesting that a filtering state of a packet be changed. 22. A program executed by a computer constituting a managed device connected to a management device via a network, wherein the management device collects a load state of the plurality of managed devices, and It checks whether or not the collected load status of the managed device corresponds to a preset load level, and if the load level has changed from the previously collected load level of the managed device, For the managed device of the notification destination registered in advance corresponding to the managed device whose level has changed, the identification information of the managed device whose load level has changed and its load level are notified, The managed device of the notification destination receiving a request to change a filtering state of a packet, and receiving a request to change a flow pattern for performing filtering from the management device. Receiving the identification information and the load level of the overloaded managed device notified from the management device, and determining the flow to be filtered based on the identification information and the load level of the overloaded managed device. Performing a first process of filtering packets to the overloaded managed device based on the determined flow, and performing the first process and the second process. That is executed by a computer constituting the managed device.