KR20090052514A - Systen and method for discovering network topology, storage medium recording that method program - Google Patents

Abstract

The present invention relates to a storage medium recording a topology detection system, a topology detection method and method program. According to the present invention, it is possible to establish linkage with any router included in the network under investigation, share link state information, and determine whether link information and switches exist between routers based on the link state information. If there is a switch, the switch can be detected based on whether data link layer support or ip packet forwarding is performed, and if there is a connection between routers or between a router and a switch, the topology can be configured by connecting to an edge. As a result, you can find the correct configuration of your switches and routers quickly and accurately while reducing the load.

Description

Storage system recording network topology detection system, detection method and method program {SYSTEN AND METHOD FOR DISCOVERING NETWORK TOPOLOGY, STORAGE MEDIUM RECORDING THAT METHOD PROGRAM}

The present invention relates to a storage medium having recorded thereon a topology detection system, a detection method and a method program.

The network topology is represented by the connection of routers and switches. In this case, the routers or switches may be represented by nodes, and the connections between these devices may be represented by edges. In other words, the connection between the router and the router constituting the network, the connection between the router and the switch, and the connection between the switch and the switch can be represented by a graph composed of edges.

Conventionally, a network topology is detected with reference to a routing table included in a router. In the routing table, there is a destination (ipRouteDest) and next hop (ipRouteNextHop) items, and in the next hop (ipRouteNextHop), there are gateway addresses to all networks in the routing table. Therefore, to find the actual NextHop, search all destinations (ipRouteDest), find the network next to the actual, and find the corresponding NextHop IP. As a result, a backbone network consisting of hundreds of routers and switches can be heavily loaded.

In addition, the conventional topology detection method is a router-oriented detection method, and it cannot be said that it is an accurate topology detection method considering that the actual network is composed of a router and a switch.

In addition, in order to detect a switch in a conventional network, all devices in the IP band of a specific interface were tested for the switch. This also has a problem that it takes too much load and takes a long time in a large backbone network.

Therefore, the technical problem to be achieved by the present invention is to be able to detect the network topology while reducing the load on the backbone network.

In addition, the technical problem to be achieved by the present invention is to be able to accurately detect the network topology consisting of a router and a switch.

The topology detection system according to an embodiment of the present invention for achieving the above technical problem, by sharing the link state information with any router included in the network under investigation and having an adjacent relationship, link information between the routers and whether there is a switch A topology detection device for detecting a network topology by detecting a switch based on whether data switch layer support or IP packet forwarding is performed if a switch exists; And a topology information database that stores link state information and topology information.

In addition, a method for detecting a topology according to an embodiment of the present invention for achieving the above technical problem comprises the steps of: a) establishing an adjacent relationship with any router included in a network to be investigated and sharing link state information; b) identifying link information between routers and whether a switch exists based on link state information; c) if the switch exists, detecting the switch based on whether data link layer support or ip packet forwarding is performed; d) if there is a connection between routers or between the router and the switch may include the step of configuring the topology by connecting to the edge.

In addition, a storage medium according to an embodiment of the present invention for achieving the above technical problem is a storage medium recording a program according to the above-described method.

Therefore, according to the present invention, topology information for network management can be detected quickly. In particular, it is possible to reduce the load more quickly and to accurately configure switches and routers. You can find it.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, ".. part", "., Group" described in the specification. Terms such as "module" may be implemented in hardware or software or a combination of hardware and software.

Now with reference to the drawings with reference to the embodiment of the present invention will be described in detail.

1 is a diagram illustrating a network topology detection system 100 connected to a network according to an embodiment of the present invention.

As shown, the network topology detection system 100 may collect packet data from network equipment via an interface protocol. The topology detection system 100 may collect and store packet data from network equipment using various interface protocols such as CORBA, SNMP, and CLI.

The topology detection system 100 may form an adjacent relationship with one of the routers of the topology survey target network, thereby sharing link state information of the corresponding network. Since the link state information of the network includes connection link information between the router IP and the router, the topology detection system 100 may configure a network topology based on the link state information.

When the router is connected through a switch, the topology detection system 100 may detect an IP of the corresponding switch and detect an accurate network topology composed of the router and the switch.

More specifically, the topology detection system 100 may include a topology detection device 110 and a topology information database 120.

The topology detection apparatus 110 may collect packet data from network equipment using various interface protocols, form an adjacent relationship with one of the routers of the network under investigation, and share link state information of the corresponding network. .

The topology detecting apparatus 110 may determine link information between routers through a router link state advertisement packet, and determine whether a switch exists through a network link state advertisement packet.

The topology information database 120 may store packet data collected from the topology detection apparatus 110, and may store connection information between routers. The topology information database 120 may store connection information between all nodes on the network or accurate topology information about whether the corresponding node is a switch or a router.

More detailed information about the topology detecting apparatus 110 and the topology information database 120 will be described later.

Hereinafter, the topology detecting apparatus 110 and the topology information database 120 will be described in detail with reference to FIGS. 2, 3, 4, and 5.

As shown in FIG. 2, the topology detection apparatus 110 may include a packet collection module 111, a connection node detection module 113, a switch detection module 115, and a topology configuration module 117.

The packet collection module 111 may collect packet data using various communication protocols from network equipment such as a router. The packet collection module 111 may collect the link state advertisement packet from the router which establishes the neighbor relationship and store the link state advertisement packet in the topology information database 120 as link state information.

The connection node detection module 113 may detect connection information between routers based on the link state information.

3 and 4 are diagrams illustrating the structures of a router link state advertisement packet and a network link state advertisement packet, respectively.

The link state information may be viewed as a set of link state advertisement packets. The link state advertisement packet may be divided into a router link state advertisement packet and a network link state advertisement packet.

In the router link state advertisement packet as shown in FIG. 3, an advertising router indicates an ID of a router broadcasting the packet, and the number of links (# links) indicates the number of routers connected to the router and neighbors. Link ID may indicate the IP of a neighbor router.

Therefore, through the router link state advertisement packet, each router ID on the network, the number of routers connected in a neighbor relationship with the router, and the router IP information of the neighbor relationship can be known.

4 is a diagram illustrating a network link state advertisement packet.

As shown, in a network link state advertisement packet, an advertising router represents an ID of a router that broadcasts the packet, and an attached router indicates a router connected through the switch and the router. Can be.

That is, if a network link state advertisement packet exists, it can be seen that the router is connected to the neighbor routers through a switch.

As shown in FIG. 5, the link state information may include connection information between routers based on router link state advertisement packet information and network link state advertisement packet information.

More specifically, the connection information between routers may have router information from the x-axis and include router information on the y-axis.

The connection node detection module 113 may determine that two routers in the topology are neighboring when there is a connection from the router information to the router information on the link state information.

The connection node detection module 113 may determine whether there is a connection to the destination router for all routers on the x-axis on the link state information, and detect connection information between all routers on the network.

According to the illustrated link state information, it can be seen that the router R1 is connected to the routers R2 and R4 as neighbors, and the router R2 is connected to the router R3 as neighbors.

When the network link state advertisement packet exists as shown in FIG. 4, the switch detection module 115 may recognize that the router is connected to neighboring routers through a switch.

More specifically, in a network link state advertisement packet, an advertising router indicates an ID of a router broadcasting the packet, and an attached router is a router connected through the router and the switch. As described above.

For example, when the advertising router is R3, and the attached router is the router R4, it can be seen that the routers R3 and R4 are connected through the switch.

If it is determined that the switch exists, the switch detection module 115 may detect the addresses of the devices connected to the corresponding router (advertising router) in a broadcast period. In other words, if there is a management IP in the switch, it can detect the addresses of devices such as host PCs and routers, including the presence of a switch that is not detected as an attached router.

For example, in case of OSPF backbone network, the switch detection module 115 may obtain an IP address (ipNetToMediaNetAddress) corresponding to a physical address on SNMP. In this case, the switch detection module 115 is connected to the router (advertising router) and the broadcast section. The address of the devices can be detected.

The switch detection module 115 may extract the switch candidate by comparing the addresses of the devices connected to the broadcast interval with the addresses of the routers detected by the attached routers.

The switch detection module 115 may check whether the switch is performed by checking whether the switch candidate device supports the data link layer or performs IP packet forwarding on the OSI 7 layer. That is, the switch may be determined when the IP packet forwarding is not performed while supporting the data link layer.

For example, you can check whether the switch is read by reading the sysService and ipForwarding values on SNMP for the switch candidate device.

sysService is a 7-bit value that indicates whether the OSI 7 layer is supported for each bit. Therefore, if the lower 2 bits of sysService are 1, it may mean that the switch operates as a switch supporting the data link layer.

ipForwarding means whether to forward ip packet or not. If ipForwarding value is 0, it means switch.

When it is determined that the first router and the second router are adjacent to each other, the topology configuration module 117 may connect the second router detected as the immediately neighboring node of the first router and the first router to an edge.

When the first router and the second router are connected by a switch, the topology configuration module 117 may connect the first router and the switch by an edge and connect the switch and the second router by an edge.

The topology configuration module 117 may connect the routers and edges connected to neighboring routers in turn for all routers on the x-axis in link state information, and connect the switches and routers to the edges when the switch exists. As a result, the topology configuration module 117 can build the entire network topology.

The topology information database 120 may include a packet storage unit 121, a link state information storage unit 123, and a topology information storage unit 125.

The packet storage unit 121 may store the packet data collected from the router or the switch equipment, and may store the link state packet collected by the packet collection module 111.

The link state information storage unit 123 may store link state information.

More specifically, the link state information may be viewed as a set of link state advertisement packets. The link state advertisement packets may be classified into router link state advertisement packets and network link state advertisement packets.

More specific details have been described above and will be omitted.

The topology information storage unit 125 may store the detected topology information.

That is, the topology information storage unit 125 may store network-wide topology information. For all routers on the network, each of the routers connected to neighboring routers and edges may be connected to each other. Can be stored.

6 is a diagram illustrating a method for searching for a neighbor router and a neighbor switch according to an embodiment of the present invention.

As shown, it can be seen from the link state information that the routers R1 and R2 are connected to the neighbors and the routers R2 are connected to the routers R1 and R3 to the neighbors.

On the other hand, in the case of router R3, it can be seen that the number of neighbor routers (#LINKS) connected based on the router link state packet information is four, and each of them is R2, R4, R5, and R6 (Link ID).

In addition, in the case of router R3, it can be seen that there is a network link state packet, and that the attached routers attached through the switch are R4, R5, and R6.

At this time, if the addresses of the devices connected to the router R3 and the broadcast interval are detected, the addresses of the routers R4, R5, and R6, including the switch SW1, are detected. Since the routers R4, R5, and R6 are the neighboring routers, SW1 may be a switch candidate device.

If the switch candidate device SW1 is determined to support the data link layer or to perform IP packet forwarding, it is determined that the switch candidate device SW1 does not perform the IP packet forwarding. SW1 can be finally confirmed that the switch.

7 is a flowchart of a method for searching a network topology according to an embodiment of the present invention.

As shown, the topology detection system 100 can know the connection information between routers from the link state information (S100, S110).

More specifically, the link state information may have FROM router information on the X axis, and may provide connection information between routers by including destination (TO) router information on the Y axis.

If there is a connection from the start (FROM) router information to the destination (TO) router information on the link state information, the topology detection system 100 may determine that the two routers on the topology are neighbors.

The topology detection system 100 may sequentially detect neighboring routers with respect to routers on the X axis in link state information.

At this time, when the network link state advertisement packet is present, the topology detection system 100 may recognize that the corresponding router is connected to another router by a switch.

For example, if there is a network link state advertisement packet of router R3 and router R4 exists as an attached router in the advertisement packet, router R3 is connected to router R4 by a switch. have.

The topology detection system 100 may detect the addresses of the devices connected to the corresponding router in the broadcast interval, and the devices detected by the neighboring routers may detect the switch device candidates by comparing with the address.

The topology detection system 100 may determine whether the switch device candidate supports the data link layer or whether to perform ip packet forwarding. When the topology detection system 100 supports the data link layer or does not perform ip packet forwarding, the topology detection system 100 may confirm that the switch is a switch. There is (S130). Since the details of the switch detection have been described above, they will be omitted.

The topology detection system 100 may directly connect two routers detected as neighboring nodes to an edge, and when a switch exists between the two routers, the topology detection system 100 may configure the topology by connecting the switch and the router to the edge (S140).

The topology detection system 100 may configure all network topologies by sequentially searching for neighboring routers or neighboring switches in the same manner as described above with respect to all routers existing on the X axis on the link state information (S150). ).

In addition, the storage medium according to an embodiment of the present invention is a storage medium that records a program for executing the above-described topology detection method.

What has been described above is only an embodiment of the present invention, and the scope of the present invention is not limited thereto, and various modifications can be made to those skilled in the art. For example, the devices constituting the topology detection system and the modules constituting each device may be additionally configured or merged according to their function. In addition, the topology detection method according to an embodiment of the present invention can be configured to change the order of course. The scope of the present invention will include all the technical elements recognized as the claims described below and equivalents thereof.

1 is a diagram illustrating a topology detection system connected to a network according to an embodiment of the present invention.

2 is a detailed configuration diagram of a topology detection apparatus and a topology information database according to an embodiment of the present invention.

3 is a structural diagram of a router link state advertisement packet according to an embodiment of the present invention.

4 is a structural diagram of a network link state advertisement packet according to an embodiment of the present invention.

5 is a block diagram of link state information according to an embodiment of the present invention.

6 is a diagram illustrating a method for searching for a neighbor router and a neighbor switch according to an embodiment of the present invention.

7 is a flowchart of a method for retrieving an entire topology configuration in accordance with an embodiment of the present invention.

Claims (19)

In a topology detection system, Share link state information with any routers that are included in the network under investigation, and link state information between routers to determine link information between routers, and if a switch exists, whether to support data link layer or IP packet forwarding. A topology detection device for detecting a network topology by detecting a switch based on the detection; And Contains a topology information database that stores link state information and topology information. Topology detection system. The method of claim 1, The topology detection device, A connection node detection module for determining that the first router and the second router are neighbors when there is a connection between the first router as a from router and the second router as a to router on the link state information; And And a switch detection module configured to detect the switch by determining that the first router and the second router are connected to the switch when a network link state packet exists. Topology detection system. The method of claim 2, The switch detection module When the first router and the second router are connected through a switch, the addresses of the devices connected to the first router and the broadcast interval are detected and not detected as neighboring routers of the first router by the connection node detection module. To detect devices that do not Topology detection system. The method of claim 3, The switch detection module, If the candidate does not support the data link layer or perform ip packet forwarding, confirming that the candidate is a switch Topology detection system. The method of claim 4, wherein The switch detection module, Detecting the addresses of the devices connected to the first router and the broadcast interval through the IP address (ipNetToMediaNetAddress) information corresponding to the physical address in SNMP Topology detection system. The method of claim 5, The switch detection module, If the lower 2 bit value of sysService is 1 in SNMP, it is determined as a switch that supports data link layer. If the ipForwarding value is 0, it is determined as a switch that does not support IP packet forwarding. Topology detection system. The method of claim 2, When there is a connection between the first router and the second router, when the first router and the second router is connected to the edge, and the first router and the second router is connected through a switch, the first router And a topology configuration module connecting the switch to the edge and connecting the switch and the second router to the edge. Topology detection system. The method of claim 2, A packet collecting module for collecting a link state advertisement packet from a router in an adjacent relationship and storing the link state advertisement packet as link state information in the topology information database; Topology detection system. The method of claim 8, The link state advertisement packet A router link state advertisement packet including connection information between routers and a network link state advertisement packet including switch presence information. Topology detection system. In the topology detection method, a) establishing linkage with any router included in the network under investigation and sharing link state information; b) identifying link information between routers and whether a switch exists based on link state information; c) if the switch exists, detecting the switch based on whether data link layer support or ip packet forwarding is performed; d) configuring the topology by connecting to the edges if there is a connection between routers or between the router and the switch; Topology detection method. The method of claim 10, Step b), b-1) in the link state information, if there is a connection between the first router as a from router and the second router as a to router, determining that the first router and the second router are neighbors; And b-2) determining that the first router and the second router are connected to a switch when a network link state advertisement packet exists. Topology detection method. The method of claim 11, Step c) is c-1) if the first router and the second router are connected through a switch, detecting addresses of devices connected to the first router in a broadcast interval; And c-2) detecting a device connected to the first router in a broadcast period but not detected by the neighbor router of the first router as a switch candidate; Topology detection method. The method of claim 12, Step c) is c-3) if the candidate does not support data link layer or perform ip packet forwarding, further comprising: confirming that the candidate is a switch Topology detection method. The method of claim 13, Step c-1), Detecting the addresses of the devices connected to the first router and the broadcast interval through the IP address (ipNetToMediaNetAddress) information corresponding to the physical address in SNMP Topology detection method. The method of claim 14, Step c-3), If the lower 2 bit value of sysService is 1 in SNMP, it is determined as a switch that supports the data link layer, or if the ipForwarding value is 0, it is determined as a switch that does not support packet forwarding. Topology detection method. The method of claim 11, In step d), When there is a connection between the first router and the second router, when the first router and the second router is connected to the edge, and the first router and the second router is connected through a switch, the first Connecting the router and the switch to an edge, and connecting the switch and the second router to an edge. Topology detection method. The method of claim 10, Step a) is Establishing an adjacent relationship with any router included in the network to be investigated; And Collecting link state advertisement packets from neighboring routers and storing the link state advertisement packets as link state information; Topology detection method. The method of claim 17, The link state advertisement packet, A router link state advertisement packet including connection information between routers and a network link state advertisement packet including switch presence information. Topology detection method. A storage medium having recorded thereon a program for executing the method according to any one of claims 10 to 19.

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