JP2010154130A - Routing authentication device, routing authentication system, routing authentication method and program thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate routing authentication on a network comprising a plurality of relay nodes. <P>SOLUTION: A routing authentication device 10 transmits a packet of TTL=n to an edge node 50 constituting the network first. After receiving an acknowledgement response for the packet, the routing authentication device decreases the value of TTL of a packet to be transmitted by one at each time in a manner of n-1 and n-2, and performs routing authentication from the identification information of a relay node which has sent back a response (notice of discard of a packet) for the transmitted packet. Namely, routing is authenticated from the side of the edge node 50 in the order of a relay node 40 one hop before the edge node and a relay node 30 further one hop before it. At this time, the routing authentication device 10 omits packet transmission to a part where routing is repeated, so that the number of packets for the routing authentication can be decreased to shorten a time needed for the routing authentication. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a network route confirmation technique.

  Conventionally, a method for confirming a route by sending a packet in which a TTL (Time To Live) is set to an arbitrary value from a route confirmation device to an edge node on a network and knowing a relay node that passes when the packet flows ( Traceroute, see Non-Patent Document 1) is known. Here, TTL is a value representing the valid period of a packet, and when the relay node receives the packet, the TTL value is decreased by 1 and transferred to the next relay node. Here, when the TTL value becomes 0 as a result of the relay node decrementing the TTL value by 1, the relay node discards the packet and transmits a discard notification of the packet to the transmission source (route confirmation device). To do.

  Here, with reference to FIG. 8, a method in which the route confirmation device 100 performs route confirmation using Traceroute will be described. FIG. 8 is a diagram conceptually showing a method of route confirmation by the route confirmation device using Traceroute. Here, a case where the packet is transferred from the route confirmation device 100 to the edge node 50 through the relay nodes 20, 30,..., 40 will be described as an example. Further, the number of hops from the route confirmation device 100 to the edge node 50 is assumed to be n. First, the path confirmation device 100 transmits a packet in which the TTL is set to 1 to the edge node 50 and requests a confirmation response from the edge node 50. Here, when the packet reaches the relay node 20, the relay node 20 returns a discard notification in which the TTL is set to 0 to the route confirmation device 100. The route confirmation device 100 confirms that the relay node 20 exists on the route to the edge node 50 by receiving such a discard notification. In addition, when the relay node 20 transmits a packet to the edge node 50, the relay node 20 confirms that the relay node 20 is the first relay node that passes through (a relay node with a hop count of 1). Similarly, when the route confirmation device 100 transmits a packet in which TTL is added by 1 (that is, TTL = 2 is set), a discard notification is transmitted from the relay node 30, and the route confirmation device 100 transmits the packet to the relay node 30. Confirm that the number of hops is two.

  The route confirmation device 100 repeats the above processing until the confirmation notification from the edge node 50 can be received, thereby knowing which relay node is routed between the route confirmation device 100 and the edge node 50. Can do. That is, the route confirmation from the route confirmation device 100 to the edge node 50 can be performed. The packet transmitted here is, for example, a packet such as ICMP (Internet Control Message Protocol, see Non-Patent Document 2), UDP (User Datagram Protocol), TCP (Transmission Control Protocol), or the like. Further, as a method for simultaneously confirming routes to a plurality of edge nodes 50, there is a method for transmitting packets to a plurality of edge nodes 50 at the same time.

  Here, when the route confirmation device 100 confirms the route of the tree-structured network, the following processing is performed. FIG. 9 is a diagram illustrating a configuration example of a tree-structured network.

  In the network having such a tree structure, when the route confirmation device 100 performs route confirmation from the route confirmation device 100 to the edge node 50 (50A to 50P) by Traceroute, the route confirmation device 100 uses the edge node 50 (50A). To 50P), a packet in which the TTL values are added one by one in order is transmitted to each.

  For example, in order to confirm the route to the relay nodes 20A and 20B with the number of hops = n−3, the route confirmation device 100 transmits a packet in which the TTL is set to n−3 to the edge node 50 (50A to 50P). To do. Since the relay nodes 20A and 20B with the number of hops = n−3 discard these packets, they return a discard notification of these packets to the route confirmation device 100. That is, the relay node 20A returns a discard notification for each packet addressed to the edge node 50 (50A to 50H) to the path confirmation device 100. Further, the relay node 20B returns a discard notification for each of the packets addressed to the edge nodes 50 (50I to 50P) to the route confirmation device 100.

  Further, the path confirmation device 100 transmits the packet set to TTL = n−2 to the edge node 50 (50A to 50P) in order to confirm the path to the relay nodes 30A and 30B with the number of hops = n−2. . The relay nodes 30A and 30B with the number of hops = n−2 discard these packets, and return a discard notification of this packet to the route confirmation device 100. That is, the relay node 30A returns a discard notification for each packet addressed to the edge node 50 (50A to 50H) to the route confirmation device 100. The relay node 30B also returns a discard notification for each packet addressed to the edge node 50 (50I to 50P) to the route confirmation device 100.

Further, the path confirmation device 100 transmits the packet set to TTL = n−1 to the edge node 50 (50A to 50P) in order to confirm the path to the relay nodes 40A to 40D with the number of hops = n−1. . Then, since the relay nodes 40A to 40D with the number of hops = n−1 discard these packets, the relay node 40A sends a discard notification of each packet addressed to the edge node 50 (50A to 50D) to the route confirmation device 100. return. Further, the relay node 40B returns a discard notification for the packet addressed to the edge node 50 (50E to 50H) to the route confirmation device 100. Further, the relay node 40C also returns a discard notification for each packet addressed to the edge node 50 (50I to 50L) connected to the route confirmation apparatus 100, and the relay node 40D also connects to the edge node 50 (50M to 50P) connected to itself. A discard notification for each addressed packet is returned to the route confirmation device 100. When receiving the packet discard notification from the relay nodes 20, 30, and 40, the route confirmation device 100 determines whether the received discard notification is a packet discard notification for which a TTL value is set or which edge node 50 is addressed. 9 and the relay node that is the transmission source of the discard notification is determined, and the route as shown in FIG. 9 is grasped. Further, the path confirmation device 100 transmits a packet of TTL = n to each edge node 50 and receives a response confirmation from these edge nodes 50 to determine whether or not each edge node 50 is operating. Check.
RFC1393, Traceroute Using an IP Option, [online], [Search November 19, 2008], Internet <URL: http://www.rfcsearch.org/rfcview?lookup_type=RFC&lookup_num=1393> RFC792, INTERNET CONTROL MESSAGE PROTOCOL, [online], [November 19, 2008 search], Internet, <URL: http://www.rfcsearch.org/rfcview?lookup_type=RFC&lookup_num=792>

  However, when the route confirmation device performs route confirmation by Traceroute, it must wait for discard notifications from all the relay nodes after packet transmission. Here, the number of packets transmitted from the route confirmation device increases in proportion to the number of edge nodes and relay nodes in the network. Therefore, when the number of edge nodes and relay nodes in the network increases, each relay The waiting time for the discard notification from the node (and the response confirmation from the edge node) also becomes longer. Therefore, there is a problem that the time required for the route confirmation device to confirm the route of the network becomes longer. Such a problem is particularly conspicuous in the route confirmation of a network having a tree structure as shown in FIG.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems and reduce the time when the route confirmation device performs network route confirmation.

  In order to solve the above-described problem, the invention described in claim 1 is a network including a plurality of edge nodes and a plurality of relay nodes that transfer packets to the edge nodes. A route confirmation device that transmits a packet in which a value of (Time To Live) is set and confirms a route to which the packet is forwarded based on a packet discard notification received from a relay node that has discarded the packet. When a storage unit for storing edge node identification information and inter-node connection information, and a discard notification of a transmitted packet or an acknowledgment of reception of the packet from the edge node are received, a discard notification is issued from the route confirmation device. Alternatively, a process for transmitting a packet in which the value of the number of hops minus 1 to the transmission source node of the confirmation response is set to TTL is notified as a discard notification or Each time an acknowledgment is received, a transmission packet control unit that repeats until the TTL value becomes 1, a packet transmission unit that transmits a packet, a packet reception unit that receives a discard notification and an acknowledgment for the transmitted packet, and a transmission When a discard notification or acknowledgment for a received packet is received, the identification information of the node from which the discard notification or acknowledgment is transmitted, the TTL value set in the transmitted packet, and the destination edge node of the transmitted packet Adjacent nodes that are connected to the same edge node and that have a difference in the number of hops from the route confirmation device based on the identification information of the node and the inter-node connection information stored in the storage unit And a node to which a packet is transferred in the network based on the determination result Internode connection information indicating the number of hops from the route confirmation device of the corresponding node is created and stored in the storage unit, and the transmission packet control unit transmits the packet between the nodes. With reference to the connection information, the destination of the packet is addressed to any one of the edge nodes connected via the node that is the source of the discard notification or confirmation response.

  According to a fifth aspect of the present invention, in a network including a plurality of edge nodes and a plurality of relay nodes that transfer packets to the edge nodes, the storage for storing the identification information of the edge nodes and the internode connection information A packet with a predetermined TTL (Time To Live) value sent to the edge node, and the packet is forwarded based on the packet discard notification received from the relay node that discarded the packet. When the route confirmation device for confirming the route to be received receives a discard notification for the transmitted packet or a confirmation response for reception of the packet from the edge node, and when receiving the discard notification or confirmation response for the transmitted packet, Referring to the connection information, the packet destination is connected via the node that sent the discard notification or acknowledgment. A step of transmitting a packet addressed to any one of the edge nodes, the identification information of the source node of the discard notification or acknowledgment for the transmitted packet, the TTL value set in the transmitted packet, Based on the identification information of the destination edge node of the transmitted packet, nodes that are connected to the same edge node and that have a difference in the number of hops from the route confirmation device as one hop are adjacent nodes. The step of creating connection information between nodes indicating nodes to which packets are forwarded in the network based on the determination result and storing the information in the storage unit, and receiving the discard notification or confirmation response, The route confirmation method is repeated until the value of 1 becomes 1.

  In this way, the transmission packet control unit of the route confirmation device can set the number of hops from the route confirmation device to the edge node as n as one or more hops before the relay node connected to the edge node of the network. In this case, when transmitting a packet for confirming the number of hops = 1 to n−2 relay node, if a packet with one of the edge nodes connected via this relay node is transmitted, Good. Note that the edge node connected via the relay node is connected to the relay node in one or more hops. That is, when the route confirmation device confirms a relay node two or more hops before the edge node in route confirmation, it is not necessary to transmit a packet destined for all edge nodes in the network. Thus, for example, in the network shown in FIG. 9, when the path confirmation device transmits a packet with TTL = n−2, (1) a packet destined for any one of the edge nodes 50A to 50D (2) a packet destined for any one of the edge nodes 50E to 50H, (3) a packet destined for any one of the edge nodes 50I to 50L, and (4 ) Four packets including a packet destined for any one of the edge nodes 50M to 50P may be transmitted, and reception of a discard notification for this packet may be awaited. That is, when the route confirmation device confirms the route of the network, it is not necessary to transmit many packets, and the response time of these packets can be shortened.

  According to a second aspect of the present invention, in the route confirmation device according to the first aspect, when the packet transmission unit receives a discard notification of the packet for the first packet transmitted by the packet transmission unit, the transmission packet control unit Processing for setting the hop count +1 value from the confirmation device to the transmission source node of the discard notification in the TTL of the packet and transmitting it, every time a discard notification is received, until a confirmation response is received from the edge node When a confirmation response is received from each edge node, the transmission packet control unit starts from the first node that is the transmission source of the discard notification for the packet transmitted first by the packet transmission unit. To the relay device, the value of the hop count minus 1 is set in the TTL of the packet, and one of the edge nodes connected via the first node The process of transmitting the packet in which the over-de destined, the TTL value and executes until 1.

  By doing in this way, since the TTL value of the packet first transmitted by the route confirmation device is smaller than the number of hops to the edge node of the network, the edge node is not reached and the relay node (first node) When the packet discard notification is received from the first node, first, the route from the first node to the edge node is confirmed by Traceroute. Then, the route confirmation from the first node to the route confirmation device is performed. That is, the route confirmation device performs route confirmation from the first relay node to the edge node by Traceroute when receiving a discard notification after transmitting the first packet. Thereafter, the packet is transmitted while reducing the value of the TTL of the packet transmitted to the relay node (first node) one by one, and the route confirmation from the route confirmation device to the first node is performed. Therefore, the route confirmation device can confirm the route of the network even when the number of hops from the route confirmation device to the edge node is unknown.

  According to a third aspect of the present invention, in the route confirmation device according to the first or second aspect, the transmission packet control unit connects to the first node from the first node connected via the edge node. When receiving a discard notification related to a packet addressed to all edge nodes, a process for transmitting a packet in which the value of the number of hops minus 1 from the path confirmation device to the node that transmitted the discard notification is set to TTL is performed. Is repeated until the TTL value becomes 1, and after the packet transmission process, until the next packet is transmitted with the hop count minus 1 value set to TTL to the source node of the discard notification. During this period, a process for transmitting a packet addressed to the edge node in which the value of the number of hops to the edge node is set to TTL is executed from the route confirmation device.

  By doing in this way, the route confirmation device, after transmitting a packet, until transmitting a packet in which the value of the hop number minus 1 to the transmission source node of the discard notification of the packet is set to TTL A packet that reaches the edge node (packet addressed to the edge node) is transmitted using time. Therefore, the route confirmation device can perform the operation confirmation of the edge node by using the time between the route confirmations of the network.

  The invention according to claim 4 comprises the route confirmation device according to any one of claims 1 to 3, and a plurality of edge nodes and relay nodes that receive packets from the route confirmation device. A route confirmation system was adopted.

  By doing in this way, the path | route confirmation system containing the path | route confirmation apparatus of any one of Claim 1 thru | or 3 is realizable.

  The invention according to claim 6 is a program for causing a route confirmation device, which is a computer, to execute the route confirmation method according to claim 5.

  According to such a program, it is possible to cause a general computer to execute the route confirmation method according to claim 5.

  According to the present invention, the number of packets transmitted by the route confirmation device for confirming the route of the network can be reduced, so that the time required for confirming the route of the network can be shortened. In addition, network congestion associated with route confirmation can be suppressed.

<First Embodiment>
Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an “embodiment”) will be described by dividing it from the first embodiment to the third embodiment.

  First, the outline of the operation of the route confirmation apparatus according to the first embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a configuration example of a network (system) including a route confirmation device according to the first embodiment. Here, the network includes edge nodes 50 (50A, 50B, 50C, 50D, 50E, 50F, 50G, 50H), relay nodes 40 (40A, 40B), 30 that connect the edge nodes 50, and route confirmation. A case including the device 10 will be described as an example. Here, the route confirmation device 10 transmits a packet (test packet) in which a predetermined TTL value is set to each of the edge nodes 50 via the relay node 40 and receives a response (packet discard notification or confirmation response). Thus, the route from the route confirmation device 10 to each edge node 50 is confirmed. The route confirmation devices 10A and 10B will be described in the sections of the second embodiment and the third embodiment.

  Here, the number of hops from the route confirmation device 10 to the edge node 50 = n, the number of hops to the relay node 40 (40A, 40B) = n−1, and the number of hops to the relay node 30 = n−2. Suppose that

  (1) First, the route confirmation device 10 transmits a packet in which TTL = n is set to the edge nodes 50A to 50H. And presence of edge node 50A-50H is confirmed by reception of the confirmation response of the said packet from this edge node 50A-50H.

  (2) After confirming the presence of the edge nodes 50A to 50H, the path confirmation device 10 transmits a packet in which TTL = n−1 (a value obtained by subtracting TTL from 1) is set to the edge nodes 50A to 50H. . Then, in the route confirmation device 10, the relay node connected to the edge nodes 50A to 50D is the relay node 40A based on the reception result of the packet discard notification from the relay nodes 40A and 40B, and the edge node 50E to It is determined that the relay node connected to 50H is the relay node 40B. That is, the packet with TTL = n−1 transmitted from the route confirmation device 10 does not reach the edge nodes 50A to 50H, and is discarded at the relay nodes 40A and 40B with the number of hops = n−1. Therefore, the route confirmation device 10 receives a discard notification from the relay node 40A that the packets destined for the edge nodes 50A to 50D are discarded at the relay node 40A, whereby the edge nodes 50A to 50D are connected to the relay node 40A. It can be confirmed. Similarly, the route confirmation device 10 receives a discard notification from the relay node 40B that the packets addressed to the edge nodes 50E to 50H are discarded at the relay node 40B, and the edge nodes 50E to 50H thereby receive the relay node. It can confirm that it connects with 40B.

  (3) Next, the route confirmation device 10 transmits a packet in which TTL = n−2 is set in order to check the relay node 30 one hop before the relay nodes 40A and 40B. Here, the path confirmation device 10 transmits, for example, a packet addressed to the edge node 50D and a packet addressed to the edge node 50G with TTL = n−2, and relay nodes 40A and 40B according to a discard notification from the relay node 30. The relay node 30 to be connected to is determined.

  That is, the route confirmation device 10 confirms that the relay node 40A is connected to the edge nodes 50A to 50D and the relay node 40B is connected to the edge nodes 50E to 50H by the process (2) described above. . Therefore, the path confirmation device 10 has TTL = n−2 and a packet destined for one of the edge nodes 50A to 50D (for example, the edge node 50D) and one of the edge nodes 50E to 50H (for example, the edge node). 50G) as a destination. In other words, the route confirmation device 10 does not need to transmit packets addressed to all the edge nodes 50A to 50H. Then, the route confirmation device 10 receives the discard notification of these packets from the relay node 30, and confirms that the relay nodes 40A and 40B are connected to the relay node 30 based on the reception result.

  Although illustration is omitted here, if there is a relay node (that is, a relay node with the number of hops = n−3) one hop before the relay node 30 in the network, the relay node and the relay node 30 When checking the connection, the following should be done. That is, since the route confirmation device 10 knows that the relay node 30 is a relay node that forwards packets addressed to the edge nodes 50A to 50H from the result of the discard notification for the packet with TTL = n−2, the edge node 50A to A packet of TTL = n−3 destined for any one of 50H is transmitted. Then, when receiving the discard notification of the packet from the relay node with the number of hops = n−3, it is confirmed from the reception result to which relay node the relay node with the number of hops = n−3 is connected. .

  By executing the processing as described above, the route confirmation device 10 can reduce the number of packets to be transmitted to confirm the relay node (route) from the route confirmation device 10 to the edge node 50 in the network. it can. Therefore, the time required for confirming the network route can be shortened.

<Configuration>
Next, the configuration of such a route confirmation apparatus 10 will be described with reference to the block diagram of FIG. FIG. 2 is a block diagram showing the configuration of the route confirmation device of FIG.

  As shown in FIG. 2, the function of the route confirmation device 10 is roughly divided into a processing unit 11, a communication unit 12, a storage unit 13, and an input / output unit 14.

  The processing unit 11 controls the entire route confirmation device 10. Here, the processing unit 11 mainly transmits a packet addressed to the edge node 50 from the route confirmation device 10 to the edge node 50 based on a packet response (packet discard notification). Check the route. The communication unit 12 transmits the packet output from the processing unit 11 to the edge node 50 and receives a response to the packet from the relay nodes 30 and 40 (see FIG. 1). The storage unit 13 stores identification information (address) of the edge node 50 in the network, a route (internode connection information 131) confirmed by the processing unit 11, and the like. The input / output unit 14 is an input / output interface for inputting various instructions to the route confirmation device 10 and outputting information stored in the storage unit 13 to an external device.

  The processing unit 11 is realized by a program execution process by a CPU (Central Processing Unit) included in the route confirmation device 10 or a dedicated circuit. The communication unit 12 includes a communication interface such as a NIC (Network Interface Card). Further, the storage unit 13 includes a storage medium such as a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), and a flash memory. The input / output unit 14 includes an input / output interface. When the route confirmation device 10 is realized by a program execution process, the storage unit 13 stores a program for realizing the function of the route confirmation device 10.

  The processing unit 11 of the route confirmation device 10 includes a control unit 111, a transmission packet control unit 112, an inter-node connection determination unit 113, and a display processing unit 114.

  The control unit 111 controls the entire processing unit 11. Further, the transmission packet control unit 112 sends a response of a packet transmitted to the edge node 50 via the communication unit 12 (discard notification from the relay nodes 30 and 40 (see FIG. 1) or confirmation response from the edge node 50). When the packet is received, a packet is generated in which the value of hop count-1 to the node (relay node or edge node 50) that has returned this response is set to TTL. Then, the generated packet is transmitted via the packet transmission unit 121. Such processing is repeated until the value of TTL becomes 1. At this time, the transmission packet control unit 112 sets the destination of this packet to one of the edge nodes 50 connected to the relay node that has returned this response. For example, when the relay nodes that have returned a packet discard notification as a response are the relay nodes 30A and 30B in FIG. 9, the edge nodes 50 connected to the relay node 30A are the edge nodes 50A to 50H. The edge nodes 50 connected to the relay node 30B are edge nodes 50I to 50P. Therefore, when the transmission packet control unit 112 transmits a packet with TTL = n−3, it transmits a packet in which any one of the edge nodes 50A to 50H is set and a packet in which any one of the edge nodes 50I to 50P is set. do it. Note that what kind of edge node 50 is connected to the relay node 30 is determined by the inter-node connection information 131 (each of the networks) created by the inter-node connection determination unit 113 based on the response to the packet transmitted so far. This can be confirmed by referring to the information) showing the connection relationship between the nodes.

  The inter-node connection determination unit 113 refers to the response (discard notification or confirmation response) received from each node (relay node 30, 40 or edge node 50) via the communication unit 12, and determines the connection relationship between the nodes. To do. That is, when the transmission packet control unit 112 transmits a packet to each node, the transmission packet control unit 112 temporarily stores the identification information of the destination edge node 50 of the transmission packet and the TTL value in the storage unit 13. Upon receiving the response to the transmission packet, the internode connection determination unit 113 stores the identification information and the TTL value of the destination edge node 50 of the transmission packet stored in the storage unit 13, and the storage unit 13. Using the stored inter-node connection information 131, the node connected to the same edge node 50 as the destination edge node 50 of the transmission packet among the transmission source nodes of the response of the transmission packet, and the difference in the number of hops Are determined as adjacent nodes. Then, the determination result is written in the inter-node connection information 131.

  For example, in the example illustrated in FIG. 1, the route confirmation device 10 determines that the relay nodes with the hop count = n−1 are the relay nodes 40A and 40B according to the response to the transmission packet with TTL = n−1. It is confirmed that 40A is connected to the edge nodes 50A to 50D, and the relay node 40B is connected to the edge nodes 50E to 50H. In this case, consider a case where the route confirmation device 10 transmits a packet with TTL = n−2 to the edge nodes 50D and 50G. Here, since the nodes one hop ahead of the relay node 30 are the relay nodes 40A and 40B, the relay nodes 40A and 40B are candidates for the relay node connected to the relay node 30. Here, when the route confirmation device 10 receives from the relay node 30 the discard notification of both the transmission packet addressed to the edge node 50D and the transmission packet addressed to the edge node 50G, the route confirmation device 10 30 knows that it is connected to the relay nodes 40A and 40B, so that information is written in the internode connection information 131 on the assumption that these nodes are adjacent to each other.

  The display processing unit 114 in FIG. 2 reads the contents of the internode connection information 131 via the control unit 111 based on the instruction input from the input / output unit 14. Then, the read contents are output to an external output device (for example, a liquid crystal monitor) via the input / output unit 14. Thereby, the user of this route confirmation device 10 can visually confirm the route of the network.

  The communication unit 12 includes a packet transmission unit 121 and a packet reception unit 122. The packet transmission unit 121 transmits the packet output from the transmission packet control unit 112 via the control unit 111 to the edge node 50. Further, the packet receiving unit 122 receives the confirmation response from the edge node 50 and the packet discard notification from the relay nodes 30 and 40, and outputs them to the control unit 111.

  The storage unit 13 stores internode connection information 131 and edge node information 132.

  The inter-node connection information 131 is information indicating a route from the route confirmation device 10 to each edge node 50, which edge node 50 is connected to which relay node, which relay node is connected, This is information indicating the number of hops from the route confirmation device 10 of each node. This inter-node connection information 131 is updated every time the inter-node connection determination unit 113 confirms the connection state between the nodes, and finally the path from the path confirmation device 10 to each edge node 50 (the connection relation between the nodes). ) (For example, a network configuration diagram illustrated in FIGS. 1 and 9) is described.

  The edge node information 132 is information indicating identification information (for example, address information of the edge node 50) of the edge node 50 in the network. The edge node information 132 is input via the input / output unit 14 in advance.

  The input / output unit 14 outputs an output result from the processing unit 11 to an external device (for example, an output device), and outputs information input from an input device (not shown) to the processing unit 11.

<Processing procedure>
Next, the processing procedure of such a route confirmation apparatus 10 will be described using FIG. 3 with reference to FIG. FIG. 3 is a flowchart showing a processing procedure of the route confirmation apparatus of FIG. Here, it is assumed that the edge node information 132 has already been input via the input / output unit 14. Further, it is assumed that the number n of hops from the route confirmation device 10 to each edge node 50 has been set in the route confirmation device 10.

  First, based on an instruction input from the input / output unit 14 of the route confirmation device 10, the transmission packet control unit 112 transmits a packet (test packet) in which TTL = n is set to each edge via the control unit 111 and the packet transmission unit 121. It transmits to the node 50 (S11). The identification information of the edge node 50 that is the destination of the packet at this time is read from the edge node information 132 and set.

  Then, the transmission packet control unit 112 waits for reception of a response confirmation from each edge node 50 (S12). When receiving a response confirmation from each edge node 50 (Yes in S12), the transmission packet control unit 112 stores the reception result in the storage unit 13 Is stored in the inter-node connection information 131. If a response confirmation cannot be received even after a predetermined time has elapsed since the packet was transmitted in S11, that fact is stored in the internode connection information 131. Then, the transmission packet control unit 112 generates a packet addressed to each edge node 50 (S13), reduces the TTL value of this packet by 1 from the previously set value, and transmits the packet to the edge node 50 (S14). ). That is, the transmission packet control unit 112 transmits a packet that reaches a node one hop before the edge node 50 (for example, the relay nodes 40A and 40B in FIG. 1) as viewed from the route confirmation device 10. The transmission packet control unit 112 records the TTL value of the transmitted packet and the identification information of the destination edge node 50 in a predetermined area of the storage unit 13.

  Next, the transmission packet control unit 112 waits for reception of the packet discard notification from each relay node for the packet transmitted in S14 (S15). Here, when a discard notification is received from each relay node (Yes in S15), the inter-node connection determination unit 113 refers to the discard notification and the inter-node connection information 131 created so far, and refers to the discard notification. The relay node adjacent to the source relay node is determined, and the internode connection information 131 is created (S16). Details of the inter-node connection determination process in S16 will be described later.

  Next, when the transmission packet control unit 112 confirms that the TTL value of the previously transmitted packet is not 1 (No in S17), it generates a packet addressed to any one of the edge nodes 50 connected via this relay node. (S18). On the other hand, when the TTL value of the previously transmitted packet is 1 (Yes in S17), the transmission packet control unit 112 ends the process. That is, the route confirmation device 10 ends the processing because all the routes have been confirmed up to the first-hop relay node.

  Subsequently to S18, the transmission packet control unit 112 decreases the value of TTL by 1, and transmits the packet generated in S18 (S19). Then, the process returns to S15 and waits for reception of a discard notification of the packet from each relay node.

  Here, the details of the inter-node connection determination process in S16 will be described with reference to FIG. For example, in the network configuration shown in FIG. 1, the route confirmation device 10 receives a discard notification of packets addressed to the edge nodes 50A to 50D from the relay node 40A, and notifies the discard notification of the packets of the edge nodes 50E to 50H from the relay node 40B. When received, the inter-node connection determination unit 113 determines the connection relationship between the nodes as follows. That is, when receiving a packet discard notification addressed to the edge nodes 50A to 50D from the relay node 40A, the transmission packet control unit 112 in FIG. 2 refers to the internode connection information 131 and determines the number of hops of the edge nodes 50A to 50D ( When n) is confirmed, the difference from the number of hops with the relay node 40A is 1, so the relay node 40A determines that the node is adjacent to the edge nodes 50A to 50D. Similarly, when the transmission packet control unit 112 receives a discard notification of packets addressed to the edge nodes 50E to 50H from the relay node 40B, the inter-node connection determination unit 113 refers to the inter-node connection information 131 and determines the edge When the number of hops (n) of the nodes 50E to 50H is confirmed, the difference in the number of hops from the relay node 40B is 1. Therefore, the internode connection determination unit 113 determines that the relay node 40B is connected to the node adjacent to the edge nodes 50E to 50H. to decide. Then, the inter-node connection information 131 writes this determination result in the inter-node connection information 131.

  Similarly, when the path confirmation device 10 of FIG. 1 receives a discard notification of packets addressed to the edge nodes 50D and 50G from the relay node 30, the internode connection information 131 is referred to and the relay nodes 40A and 40B The number of hops (n-1) and the edge node 50 connected to each of the relay nodes 40A and 40B are confirmed. Here, the difference between the number of hops between the relay node 30 and the relay nodes 40A and 40B is 1, and the edge node 50D is connected to the relay node 40A, and the edge node 50G is connected to the relay node 40B. Therefore, the internode connection determination unit 113 determines that the relay node 30 is a node adjacent to the relay nodes 40A and 40B.

  According to the route confirmation device 10 described above, when confirming a route in the network, for route confirmation of a relay node within n-2 hops from the route confirmation device 10, a packet addressed to all the edge nodes 50 is used. No need to send. Therefore, the route confirmation device 10 can reduce the number of packets to be transmitted for route confirmation, and can also reduce the waiting time for confirmation of reception of the packet, thereby reducing the time required for route confirmation.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. The route confirmation device 10A according to the second embodiment transmits a packet in which an arbitrary value is set as the TTL value of the packet transmitted to the edge node 50 first. Then, the route confirmation device 10A is characterized in that the subsequent processing is changed depending on whether or not the response to the packet is a confirmation response (that is, whether the response has reached the edge node 50). An outline of the processing procedure at this time will be described with reference to FIG. FIG. 4 is a diagram illustrating an outline of a processing procedure of the route confirmation device according to the second embodiment. The network configuration is the same as in FIG.

  In the network configuration illustrated in FIG. 4, the path confirmation device 10A first transmits, for example, packets set with TTL = 3 to the edge nodes 50A to 50P. Here, in the network configuration illustrated in FIG. 4, the route confirmation device 10 </ b> A receives a discard notification of the packet from each of the relay nodes 40 </ b> A to 40 </ b> D (the number of hops from the route confirmation device 10 = 3). Thereby, the route confirmation device 10A confirms that the number of hops to the edge node 50 is larger than three. (1) Therefore, the route confirmation device 10A first confirms the route to the edge node 50 by the conventional Traceroute. That is, the route confirmation device 10A transmits a packet in which the TTL value is incremented by one. Then, the internode connection information 131 is updated based on the response to the transmitted packet with the TTL value increased. Such a process is repeated until an acknowledgment from each edge node 50 can be received. For example, in the case of the network configuration shown in FIG. 4, since the number of hops of the edge node 50 is 4, when a packet in which TTL = 4 is set is transmitted, an acknowledgment from each edge node 50 is received. Then, the route confirmation device 10A confirms the route as indicated by reference numeral 401 based on the discard notification from the relay node 40 (40A to 40D) and the response confirmation from each edge node 50 for the packet transmitted first. The inter-node connection determination unit 113 records the confirmed path in the inter-node connection information 131.

  (2) Next, the route confirmation device 10A confirms the route from the relay node 40 to the route confirmation device 10A while decreasing the value of TTL one by one as in the first embodiment. That is, the route confirmation device 10A transmits a packet with TTL = 2 → receives a discard notification of this packet from the relay node 30 (30A, 30B) → transmits a packet with TTL = 1 after confirming reception → a notification of discard of this packet Is repeated from the relay node 20 (20A, 20B), thereby confirming a route as indicated by reference numeral 402. The inter-node connection determination unit 113 records the confirmed path in the inter-node connection information 131.

  When the route confirmation device 10A transmits a packet with TTL = 2, the edge node 50 connected via the relay node 40 (40A to 40D) with the number of hops = 3 based on the route confirmed in (1). Confirm. Based on the confirmation result, the packet addressed to any one of the edge nodes 50A to 50D, the packet addressed to any one of the edge nodes 50E to 50H, and any one of the edge nodes 50I to 50L. A packet addressed to the edge node 50 and a packet addressed to any one of the edge nodes 50A to 50D are generated and transmitted. Further, when transmitting a packet with TTL = 1, a packet addressed to any one of the edge nodes 50A to 50H and the edge nodes 50I to 50I through a path confirmed from the contents of the discard notification for the packet with TTL = 2. A packet addressed to any one of the edge nodes 50 of 50P may be generated and transmitted.

  By doing so, the route confirmation device 10A can confirm the route even when the number of hops to each edge node 50 is not known, and the number of packets transmitted for route confirmation is also reduced. it can. Therefore, the time required for the route confirmation device 10A to confirm the route can be reduced.

<Processing procedure>
Next, the processing procedure of the route confirmation apparatus 10A will be described with reference to FIG. FIG. 5 is a flowchart illustrating a processing procedure of the route confirmation device according to the second embodiment.

  First, the transmission packet control unit 112 of the route confirmation device 10A sets TTL = n (n is an arbitrary natural number of 2 or more), and transmits a packet to each edge node 50 (S21). Next, when the transmission packet control unit 112 receives a discard notification of this packet as a response to the packet transmitted to each edge node 50 (Yes in S22), information regarding this discard notification is sent to the inter-node connection information 131. Remember. Next, the transmission packet control unit 112 transmits a packet whose TTL value is increased by 1 to each edge node 50 (S24), and waits for reception of an acknowledgment or a discard notification for the transmitted packet (S25). When the confirmation response or the discard notification is received (Yes in S25), the inter-node connection determination unit 113 determines the connection relationship between the nodes based on the received confirmation response or the discard notification, and the inter-node connection information 131 is obtained. Is created (S26). When the transmission packet control unit 112 confirms that the confirmation responses from all the edge nodes 50 have been received within a predetermined time after transmitting the packet in S24 (Yes in S27), the same as S13 and subsequent steps in FIG. Perform the process. That is, the route confirmation device 10A performs route confirmation from the relay node with the number of hops = n−1 to the relay node with the number of hops = 1.

  Also, in S27, the transmission packet control unit 112 did not receive confirmation responses from all the edge nodes 50 within a predetermined time after transmitting the packet in S24 (No in S27), but all received responses were confirmed. When the response is confirmed (Yes in S28), that is, when the received response does not include a packet discard notification, the same processing as S13 and after in FIG. 3 is performed. That is, although the transmission packet control unit 112 transmits a packet to each edge node 50, there may be a case where confirmation responses cannot be received from all the edge nodes 50 due to a failure of the edge node 50 or the like. In such a case, the path confirmation device 10A can confirm that all received responses are confirmation responses (that is, the received response does not include a discard notification), and after S13 in FIG. A similar process is executed.

  On the other hand, when all of the responses received by the transmission packet control unit 112 are not confirmation responses in S28 (No in S28), that is, when the received response includes a discard notification of the packet transmitted in S24. , Return to S24.

  When a confirmation response is received as a response to the packet transmitted to each edge node 50 in S22 (No in S22) instead of the packet discard notification (Yes in S23), the process proceeds to S27, and all the network It is confirmed whether or not a confirmation response from the edge node 50 has been received.

  On the other hand, when the transmission packet control unit 112 has not yet received the discard notification and the confirmation response (No in S22 → No in S23), the process returns to S22 and waits for reception of any one of these responses.

  According to the route confirmation device 10A described above, route confirmation can be performed even when the number of hops to each edge node 50 is not known, and the number of packets transmitted for route confirmation can be reduced. Therefore, the time required for the route confirmation device 10A to confirm the route can be reduced.

  Note that the route confirmation device 10A is also applicable when performing route confirmation of a network including the edge nodes 50 having different hop numbers as illustrated in FIG. FIG. 6 is a diagram illustrating an example of a network configuration including a route confirmation device according to the second embodiment. The network configuration in FIG. 6 uses edge nodes 50A and 50B instead of the relay nodes 40A and 40B in the network configuration in FIG. That is, the network has a configuration in which the edge node 50 with the number of hops = 3 and the edge node 50 with the number of hops = 4 are mixed. In such a network configuration, when the route confirmation device 10A first transmits a packet with TTL = 3, it receives confirmation responses from the edge nodes 50A and 50B, but sends a packet discard notification from the relay nodes 40C and 40D. Will receive. Also in such a case, the route confirmation device 10A transmits the packet by increasing the TTL value by 3 from 1, and performs route confirmation by Traceroute. For example, the path confirmation device 10A transmits a packet with TTL = 3, and after receiving this response, transmits a packet with TTL = 4 set to each edge node 50. The edge node 50 that is the destination of the packet to be transmitted here may be the edge nodes 50A to 50P, but is the edge node 50 excluding the edge nodes 50A and 50B that have already received the acknowledgment, that is, the edge nodes 50I to 50P. Is preferred. This is because the number of packets transmitted by the route confirmation device 10A for route confirmation can be reduced, and the waiting time for receipt confirmation of the packet can be reduced, thereby reducing the time required for route confirmation.

  In this way, the route confirmation device 10 </ b> A increases the TTL value by 1 by Traceroute and confirms the route as indicated by reference numeral 601. Thereafter, the route confirmation device 10A confirms the route from the edge nodes 50A and 50B and the relay node 40 to the route confirmation device 10A while decreasing the value of TTL one by one as in the case of FIG. . That is, the route confirmation device 10A transmits a packet with TTL = 2 → receives a discard notification of this packet from the relay node 30 (30A, 30B) → transmits a packet with TTL = 1 after confirming reception → a notification of discard of this packet Is repeated from the relay node 20 (20A, 20B) to confirm a route as indicated by reference numeral 602. Then, by combining these routes, inter-node connection information 131 for the entire network is created.

  According to the route confirmation device 10A described above, it is possible to confirm the route to the edge node 50 having various hop counts. Further, the number of packets transmitted by the route confirmation device 10A for route confirmation can be reduced, and the waiting time for confirmation of reception of the packet can be reduced, so that the time required for route confirmation can be reduced.

<Third Embodiment>
Next, the route confirmation device 10B of the third embodiment will be described with reference to FIG. The route confirmation device 10B according to the third embodiment first transmits a packet with TTL = n−1, and transmits a packet with TTL = n by using a free time until transmission of the next packet. Features. In other words, the route confirmation device 10B is characterized in that the operation of each edge node 50 is confirmed using the idle time for route confirmation in the network.

  FIG. 7 is a diagram conceptually illustrating an operation outline of the route confirmation device 10B according to the third exemplary embodiment. As shown in FIG. 7, the route confirmation device 10B first sets TTL = n−1, transmits each edge node 50 as a destination, and relays nodes (relay nodes 20, 30,. 40) Waiting for reception of the discard notification of the packet. Here, the time until the path confirmation device 10B completes the reception of the discard notification of this packet after transmitting the packet with TTL = n−1, that is, the free time until the next packet with TTL = n−2 is transmitted. Using 701, the route confirmation device 10B transmits a packet in which TTL = n is set to the edge node 50. Further, after transmitting the packet with TTL = n−2, the time until the reception of the discard notification of the packet is completed, that is, the free time 702 until the next packet with TTL = n−3 is transmitted is used. The path confirmation device 10B transmits a packet addressed to the edge node 50 that has not yet been transmitted among packets in which TTL = n is set. That is, the route confirmation device 10B transmits a packet for confirming the operation of the edge node 50 using the waiting time until the reception of the discard notification from the relay node is completed, so that the route confirmation to each edge node 50 is confirmed. In addition, the operation check can be performed efficiently.

  In each of the above-described embodiments, the route confirmation devices 10, 10 </ b> A, and 10 </ b> B may omit the operation confirmation of each edge node 50 and perform only the route confirmation to each edge node 50. That is, when the number of hops from the route confirmation devices 10, 10A, 10B to the edge node 50 is n, the route confirmation devices 10, 10A, 10B may omit transmission of packets with TTL = n.

  In each of the embodiments described above, the route confirmation devices 10, 10A, and 10B perform route confirmation to each edge node 50, but the present invention is not limited to this. For example, when each relay node receives a packet, if it is a node that can return a confirmation response of the packet, the route to the relay node is confirmed based on the confirmation response from the relay node. May be.

  Further, in each of the above-described embodiments, when the inter-node connection information 131 is created, the path confirmation devices 10, 10A, 10B transmit a packet addressed to any one of the edge nodes 50 connected via the relay node. However, it is not limited to this. For example, in the network configuration shown in FIG. 1, when the route confirmation devices 10, 10 </ b> A, 10 </ b> B transmit packets with TTL = n−2, packets destined for the relay nodes 40 </ b> A, 40 </ b> B may be transmitted. By doing this as well, it can be seen which relay node 30 with the hop number = n−2 is adjacent to which relay node 40 with the hop number = n−1. Further, when selecting the edge node 50 that is the destination of the packet, the route confirmation devices 10, 10A, and 10B may select a plurality of edge nodes 50 from the group of edge nodes 50 connected to the relay node as the destination. For example, in the network configuration shown in FIG. 1, when the route confirmation devices 10, 10A, and 10B transmit a packet with TTL = n−2, the route confirmation devices 10, 10A, and 10B connect to the edge nodes 50C and 50D and the relay node 40B that are connected to the relay node 40A. The edge nodes 50G and 50H to be connected may be selected as a packet destination.

  The route confirmation devices 10, 10A and 10B according to the present embodiment can be realized by a program for executing the processing as described above, and the program is stored in a computer-readable recording medium (CD-ROM or the like). Can be provided.

It is the figure which showed the structural example of the network containing the route confirmation apparatus of 1st Embodiment. It is the block diagram which showed the structure of the route confirmation apparatus of FIG. It is the flowchart which showed the process sequence of the route confirmation apparatus of FIG. It is a figure explaining the outline | summary of the process sequence of the route confirmation apparatus of 2nd Embodiment. It is a flowchart which shows the process sequence of the route confirmation apparatus of 2nd Embodiment. It is the figure which showed the example of a network structure containing the route confirmation apparatus in 2nd Embodiment. It is the figure which showed notionally the operation | movement outline | summary of the route confirmation apparatus of 3rd Embodiment. It is the figure which showed notionally the method in which a route confirmation apparatus performs route confirmation by Traceroute. It is the figure which showed the structural example of the network of a tree structure.

Explanation of symbols

10, 10A, 10B Route confirmation device 11 Processing unit 12 Communication unit 13 Storage unit 14 Input / output unit 20 (20A, 20B), 30 (30A, 30B), 40 (40A, 40B, 40C) Relay node 50 (50A-50P) ) Edge node 111 Control unit 112 Transmission packet control unit 113 Internode connection determination unit 114 Display processing unit 121 Packet transmission unit 122 Packet reception unit 131 Internode connection information 132 Edge node information

Claims (6)

In a network including a plurality of edge nodes and a plurality of relay nodes that transfer packets to these edge nodes, a packet in which a predetermined TTL (Time To Live) value is set is transmitted to the edge node. A route confirmation device for confirming a route to which the packet is transferred based on the discard notification of the packet received from the relay node that has discarded
A storage unit for storing identification information of the edge node and inter-node connection information;
When receiving the discard notification of the transmitted packet or the acknowledgment of reception of the packet from the edge node, the number of hops minus 1 from the path confirmation device to the node that is the source of the discard notification or the acknowledgment is A transmission packet control unit that repeats the process of transmitting a packet whose value is set to TTL every time the discard notification or the confirmation response is received until the value of this TTL becomes 1,
A packet transmission unit for transmitting the packet;
A packet receiver for receiving the discard notification and the confirmation response for the transmitted packet;
When a discard notification or confirmation response for the transmitted packet is received, the identification information of the node that sent the discard notification or confirmation response, the TTL value set in the transmitted packet, and the destination address of the transmitted packet A node that is connected to the same edge node based on the identification information of the edge node and the internode connection information stored in the storage unit, and the difference in the number of hops from the route confirmation device is 1 hop The nodes are determined as adjacent nodes, and based on the determination result, the internode connection information indicating the number of hops from the node to which the packet is transferred in the network and the route confirmation device of the node is created, An inter-node connection determination unit that stores in the storage unit,
When transmitting the packet, the transmission packet control unit refers to the internode connection information, and connects the destination of the packet via the node that is the source of the discard notification or the confirmation response. A route confirmation apparatus for addressing any one of the edge nodes. When the packet transmission unit receives a discard notification of the packet for the first packet transmitted by the packet transmission unit, the transmission packet control unit determines that the number of hops from the route confirmation device to the node that transmitted the discard notification is +1. The process of setting the value to the TTL of the packet and transmitting it is executed until the confirmation response from the edge node is received each time the discard notification is received,
When the confirmation response from each of the edge nodes is received, the transmission packet control unit starts from the first node that is the transmission source of the discard notification for the packet transmitted first by the packet transmission unit. To the number of hops to the relay device minus 1 is set in the TTL of the packet, and a process of transmitting a packet destined for any one of the edge nodes connected via the first node is performed. 2. The route confirmation apparatus according to claim 1, wherein the route confirmation device is executed until the value of the TTL becomes 1. When the transmission packet control unit receives a discard notification regarding packets addressed to all edge nodes connected to the first node from the first node connected via the edge node, the transmission packet control unit, from the path confirmation device, The process of transmitting a packet in which the value of the number of hops minus 1 to the transmission source node of the discard notification is set to TTL is repeated every time the discard notification is received until the value of this TTL becomes 1.
After the transmission processing of the packet, next, from the route confirmation device to the edge node, until a packet in which the value of the number of hops minus 1 to the transmission source node of the discard notification is set to TTL is transmitted. The route confirmation apparatus according to claim 1 or 2, wherein a process for transmitting a packet addressed to an edge node in which the value of the number of hops is set to TTL is executed.   4. A route confirmation system comprising: the route confirmation device according to claim 1; and a plurality of edge nodes and relay nodes that receive packets from the route confirmation device. In a network including a plurality of edge nodes and a plurality of relay nodes that transfer packets to the edge nodes, the network includes a storage unit that stores the identification information of the edge nodes and inter-node connection information. A path for transmitting a packet in which a predetermined TTL (Time To Live) value is set and confirming a path through which the packet is transferred based on the discard notification of the packet received from the relay node that discarded the packet The confirmation device
Receiving the discard notification for the transmitted packet or an acknowledgment of receipt of the packet from the edge node;
When the discard notification of the transmitted packet or the confirmation response is received, the destination of the packet is connected to the destination of the packet via the node of the source of the discard notification or the confirmation response with reference to the internode connection information. A step of transmitting a packet addressed to one of the edge nodes;
The same edge based on the identification information of the source node of the discard notification or acknowledgment for the transmitted packet, the TTL value set in the transmitted packet, and the identification information of the destination edge node of the transmitted packet Nodes that are connected to the node and that have a difference in the number of hops from the route confirmation device are determined as adjacent nodes, and the packet is transferred in the network based on the determination result A path confirmation method that repeats the step of creating connection information between the nodes indicating nodes and storing the information in the storage unit until the TTL value becomes 1 each time the discard notification or the confirmation response is received. The program for making the said route confirmation apparatus which is a computer perform the route confirmation method of Claim 5.

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