Network restoration time estimation device, restoration time estimation method, and program

Abstract

To provide a restoration time estimation device that can easily estimate restoration time, when a communication failure occurs in a network.SOLUTION: A restoration time estimation device includes a setting information acquisition unit that acquires setting information about a routing protocol assigned to each of a plurality of interfaces in a network device connected to a communication line of a network, a parameter extraction unit that extracts a specific parameter portion related to a dead timer value from the setting information, and a restoration time estimation unit that estimates the restoration time when a failure occurs for each of the plurality of interfaces based on the specific parameter portion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a recovery time estimation device, a recovery time estimation method, and a program when a failure occurs in a network. [Background technology]

[0002] Patent Document 1 discloses a network design device that constructs / reproduces, as a network model, a network system that matches a network system currently in operation, based on network management information collected by a network management system. By constructing a network model that matches a network currently in operation using the network management information currently in operation collected by the network management system, it becomes possible to evaluate the satisfaction of performance requirements required by communication operations and to verify methods for avoiding the impact that occurs when network equipment failures occur. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-208633 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional methods such as that disclosed in Patent Document 1 require the preparation of multiple network devices and the construction of a simulated network model that can transfer packets from a network device at a first location to a network device at a second location, which poses the problem that when a failure occurs in communication via the network, it is not possible to easily estimate the recovery time until the communication is restored.

[0005] Therefore, in view of the above, an object of the present invention is to provide a recovery time estimation device, a recovery time estimation method, and a program that can easily estimate the recovery time when a communication failure occurs in a network. [Means for solving the problem]

[0006] A recovery time estimation device of the present invention is connected to network devices that constitute a network, and estimates a recovery time required for communication to be restored when a failure occurs in the network, and is characterized by comprising: a setting information acquisition unit that acquires setting information about a routing protocol assigned to each of a plurality of interfaces in the network device that is connected to a communication line of the network; a parameter extraction unit that extracts a specific parameter portion related to a dead timer value from the setting information; and a recovery time estimation unit that estimates the recovery time when the failure occurs for each of the plurality of interfaces based on the specific parameter portion.

[0007] The recovery time estimation method of the present invention is a recovery time estimation method for a recovery time estimation device that is connected to network devices that make up a network and that estimates a recovery time required for communication to be restored when a failure occurs in the network, and is characterized by including the steps of: acquiring configuration information about a routing protocol assigned to each of a plurality of interfaces in the network devices that are connected to communication lines of the network; extracting a specific parameter portion related to a dead timer value from the configuration information; and estimating the recovery time when the failure occurs for each of the plurality of interfaces based on the specific parameter portion.

[0008] The program of the present invention is a program for a recovery time estimation method of a recovery time estimation device that is connected to a network device that constitutes a network and estimates a recovery time until communication is restored when a failure occurs in the network, and is characterized by causing a computer to execute the steps of acquiring configuration information about a routing protocol assigned to each of a plurality of interfaces in the network device that is connected to a communication line of the network, extracting a specific parameter portion related to a dead timer value from the configuration information, and estimating the recovery time when the failure occurs for each of the plurality of interfaces based on the specific parameter portion. [Effects of the Invention]

[0009] According to the recovery time estimation device, recovery time estimation method, and computer of the present invention, a specific parameter portion related to a dead timer value is extracted from setting information related to the routing protocol of a network device, so that the recovery time when a communication failure occurs can be easily estimated for each interface of the network device based on the specific parameter portion. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a block diagram illustrating a network system to which the present invention is applied; [Figure 2] 2 is a block diagram showing each part of a restoration time estimation device configured by a terminal in the system of FIG. 1 executing a restoration time estimation operation. FIG. [Figure 3] 2 is a flowchart showing a recovery time estimation operation executed by a terminal in the system of FIG. 1; [Figure 4] FIG. 2 is a diagram showing setting information of network devices in the system of FIG. [Figure 5] FIG. 10 is a diagram showing, in table form, the results of creating a database of specific parameters extracted from the configuration information of network devices. [Figure 6]FIG. 6 is a diagram showing, in table form, an estimated recovery time for each protocol based on the specific parameter portion of the database shown in FIG. 5. [Figure 7] FIG. 6 is a diagram showing, in table form, an estimated recovery time for each interface based on the specific parameter portion of the database shown in FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0012] Fig. 1 is a block diagram illustrating a network system 10 to which the present invention is applied. The network system 10 includes multiple network devices 11, 12, 13, and 14. Although Fig. 1 shows four network devices 11, 12, and 13 as an example, the network configuration is not limited to this.

[0013] Network devices 11, 12, 13, and 14 are, for example, routers. Network device 11 has multiple interfaces (not shown) for connecting external devices, and is connected to network devices 12, 13, and 14 via communication lines 15, 16, and 17, respectively, via the multiple interfaces. Each of network devices 11, 12, 13, and 14 performs data communication using TCP / IP (Transmission Control Protocol / Internet Protocol), determines the destination of an IP packet based on an IP address, selects an optimal communication line, and transmits the IP packet using the selected communication line. A routing protocol is assigned to each of network devices 11, 12, 13, and 14 for selecting a communication line for each interface, and setting information for the assigned routing protocol is stored in a storage device (not shown).

[0014] The network device 11 is connected to a terminal 18 via a communication line 19. The terminal 18 is, for example, a PC (personal computer), and performs operations according to a program. The operations according to the program include a recovery time estimation operation that estimates the recovery time required for communication to be restored when a network failure occurs. The terminal 18 can read setting information of the routing protocol of the network device 11 via the communication line 19. By performing the recovery time estimation operation, the terminal 18 configures a recovery time estimation device that includes a setting information acquisition unit 21, a parameter extraction unit 22, a recovery time estimation unit 23, and a recovery time output unit 24, as shown in FIG. 2 .

[0015] These routing protocols include OSPF (Open Shortest Path First), BGF (Border Gateway Protocol), and EIGRP (Enhanced Interior Gateway Routing Protocol), and also include redundancy protocols such as HSRP (Hot Standby Router Protocol).

[0016] Next, the operation of terminal 18 for estimating the recovery time when a network failure occurs will be described with reference to the flowchart of FIG.

[0017] When the terminal 18 starts the recovery time estimation operation, first, it reads out the setting information about the routing protocol from the storage device of the network device 11 (step S11). Step S11 corresponds to the operation of the setting information acquisition unit 21. The setting information read out here may be the setting information output when a setting confirmation command of the network device 11 is executed.

[0018] Figure 4 shows part of the HSRP configuration information for network device 11. In the configuration information in Figure 4, "interface x / x / 1" indicates that the interface number is "x / x / 1," "ip address aaaa bbbb" indicates that the IP address is "aaaabbbb," "standby 1 ip cccc" indicates that the virtual IP address of standby group standby 1 is "cccc," and "standby 1 timers yy1 zz1" indicates that the hello timer value and hold timer value of standby group standby 1 are "yy1" (seconds) and "zz1" (seconds), respectively. The hello timer value indicates the interval between hello packets exchanged between network devices. The hold timer value is greater than the hello timer value and indicates the delay time until a network device or interface is switched when a hello packet cannot be received from another network device, and corresponds to the dead timer value. The dead timer value is a reference value for determining the period during which a hello packet cannot be received, and is set in advance.

[0019] The terminal 18 extracts specific parameter portions of the routing protocol from the configuration information read in step S11 and stores the specific parameter portions in a database (step S12). Step S12 corresponds to the operation of the parameter extraction unit 22. In the case of HSRP, the specific parameter portions extracted here are the sections of the configuration information that describe parameters related to the hello / hold timer values of each routing protocol that affect recovery operations when a failure occurs. Furthermore, the specific parameter portions are extracted for each interface number in order to estimate the recovery time for each interface. In the network device 11, interface numbers are set corresponding to each of the multiple communication lines (including communication lines 15, 16, and 17) connected to the network device 11. When the specific parameter portions to be stored in the database are displayed in a table, the row items are routing protocol names that indicate the type of routing protocol, and the column items are interface numbers. The contents of the extracted specific parameter portions are recorded where the routing protocol name and interface number match.

[0020] Figure 5 shows the specific parameters in the database in a table format. In the table format in Figure 5, "OSPF", "HSRP", "BGF", and "EIGRP" are routing protocol names. Also, "x / x / 1" and "x / x / 2" are interface numbers. Where "HSRP" and "x / x / 1" match, "standby 1 timers yy1 zz1" is displayed, corresponding to the configuration information in Figure 4. Where "OSPF" and "x / x / 2" match, "ip ospf dead-interval nn1" is displayed, and where "HSRP" and "x / x / 2" match, "standby 1 timers yy2 zz2" is displayed. "ip ospf dead-interval nn1" is the dead interval value nn1 (seconds) of the routing protocol OSPF, which corresponds to the dead timer value and indicates that the time from when Hello packets cannot be received from an OSPF network device (neighbor) until the neighbor is considered down is nn1 (seconds). In this embodiment, there is a magnitude relationship of nn1>ZZ2.

[0021] Terminal 18 estimates the recovery time of each routing protocol for each interface from the specific parameter portion stored in the database (step S13). Step S13 corresponds to the operation of recovery time estimation unit 23. The specific parameter portion stored in the database is the hello / hold timer value of the routing protocol, and since the hello / hold timer value is used as a specification for each routing protocol to cause a switching operation of the network device or interface, the recovery time is determined from the hello / hold timer value.

[0022] The terminal 18 outputs the estimated recovery time for each interface (step S14). Step S14 corresponds to the operation of the recovery time output unit 24. If multiple routing protocols are used for one interface, the maximum recovery time for each interface column in the database is output as the recovery time for that one interface. In step S14, the estimated recovery time for each interface may be displayed on a display (not shown) of the terminal 18, or the estimated recovery time for each interface may be output as audio.

[0023] For example, when a specific parameter portion is extracted as shown in Figure 5, estimating the recovery time of each routing protocol for each interface from that specific parameter portion results in the estimated recovery time shown in Figure 6, and the estimated recovery time output for each interface is determined as shown in Figure 7. In Figures 6 and 7, for interface number x / x / 1, the hold timer value zz1 (seconds) of the standby group standby 1 of protocol HSRP is estimated as the recovery time. Since only protocol HSRP is used on interface number x / x / 1, this estimated recovery time zz1 (seconds) is output as is. For interface number x / x / 2, the dead interval value nn1 (seconds) of the routing protocol OSPF is estimated as the recovery time, and the hold timer value zz2 (seconds) of the standby group standby 1 of the routing protocol HSRP is estimated as the recovery time. Since two routing protocols are used for interface number x / x / 2, the larger of the dead interval value nn1 (seconds) and the hold timer value zz2 (seconds), nn1 (seconds), is selected and output as the estimated recovery time.

[0024] In this way, in the embodiment, the hold timer value and dead interval value of the routing protocol in the configuration information of the network device correspond to the time until switching to another interface because the current interface cannot receive Hello packets, so by using the hold timer value and dead interval value, it is possible to easily obtain an estimated recovery time when a failure occurs for each interface. Another advantage is that there is no need to construct a simulated network model such as that disclosed in Cited Document 1 in order to estimate the recovery time when a failure occurs.

[0025] In the above embodiment, the hold timer value and the dead interval value indicated in the setting information of the routing protocol are directly used as the estimated recovery time, but the recovery time may be estimated by adding a delay time due to actual operational delays to the hold timer value and the dead interval value.

[0026] In the above embodiment, the network device is a router, but the recovery time estimation device of the present invention is not limited to a router and can be connected to network devices such as modems, servers, and client terminals. [Explanation of symbols]

[0027] 10 Network Systems 11~14 Network equipment 15-17, 19 Communication lines 18 devices 21 Setting information acquisition unit 22 Parameter Extraction Unit 23 Recovery time estimation section 24 Recovery time output section

Claims

1. A recovery time estimation device that is connected to a network device that configures a network and that estimates a recovery time until communication is restored when a failure occurs in the network, comprising: a setting information acquisition unit that acquires setting information about a routing protocol assigned to each of a plurality of interfaces in the network device connected to a communication line of the network; a parameter extraction unit that extracts a specific parameter portion related to a dead timer value from the setting information; a recovery time estimation unit that estimates the recovery time when the failure occurs for each of the plurality of interfaces based on the specific parameter portion; A recovery time estimation device comprising:

2. 2. The restoration time estimation device according to claim 1, further comprising a restoration time output unit that outputs the restoration time estimated by the restoration time estimation unit for each of the interfaces.

3. 2. The recovery time estimation device according to claim 1, wherein the dead timer value is a hold timer value or a dead interval timer value of the routing protocol.

4. 4. The restoration time estimation device according to claim 1, wherein the restoration time estimation unit sets the dead timer value as the restoration time.

5. 3. The recovery time estimation device according to claim 2, wherein when the recovery times are estimated for each of the types of routing protocols in each of the interfaces, the recovery time output unit outputs a maximum time among the recovery times.

6. 2. The recovery time estimation device according to claim 1, wherein the parameter extraction unit creates a database of the specific parameter portion.

7. A recovery time estimation method for a recovery time estimation device that is connected to a network device that constitutes a network and that estimates a recovery time until communication is restored when a failure occurs in the network, comprising: acquiring setting information about a routing protocol assigned to each of a plurality of interfaces in the network device connected to a communication line of the network; extracting a specific parameter portion relating to a dead timer value from the setting information; estimating the recovery time when the failure occurs for each of the plurality of interfaces based on the specific parameter portion; A recovery time estimation method comprising:

8. A program for a recovery time estimation method of a recovery time estimation device that is connected to a network device that constitutes a network and that estimates a recovery time until communication is restored when a failure occurs in the network, comprising: On the computer, acquiring setting information about a routing protocol assigned to each of a plurality of interfaces in the network device connected to a communication line of the network; extracting a specific parameter portion relating to a dead timer value from the setting information; estimating the recovery time when the failure occurs for each of the plurality of interfaces based on the specific parameter portion; A program characterized by executing the following.

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