Abstract: A non-transitory computer-readable recording medium storing therein a test program causing a computer to execute a process including acquiring a first packet and a second packet sent to a first device; transmitting, based on the acquired first packet, a third packet obtained by setting a destination of the first packet to a second device; and transmitting, based on the acquired second packet, a fourth packet obtained by setting a destination of the second packet to the second device, the fourth packet being transmitted upon elapse of a period from the transmission of the third packet and equal to a time interval between acquisition of the first packet and acquisition of the second packet.

Abstract: Only when a request formed of a plurality of request packets obtained by dividing the request is reconstructed, the request is transmitted to a survey target node that returns a response formed of a plurality of response packets obtained by dividing the response. When no response packet has been received at all from the survey target node, it is determined that any of the request packets has been discarded on a first route from a surveying node as a transmission source of the request to the survey target node. When one or more response packets have been received from the survey target node but the response cannot be reconstructed, it is determined that any of the response packets transmitted from the survey target node has been discarded on a second route from the survey target node to the surveying node as the transmission source of the request packets.

Abstract: A network group determination device includes an acquisition section, a comparison section and a determination section. The acquisition section acquires first communication information representing a state of communication between a first repeater on a network and a specific network group on the network, and second communication information representing a state of communication between a second repeater on the network and the network group. The comparison section makes a comparison of a difference between the first communication information and the second communication information to third communication information between the first repeater and the second repeater. The determination section makes, according to a result of the comparison by the comparison section, a determination of a position of the network group with respect to the first repeater and the second repeater.

Abstract: A CPU executes a process including determining a core node among plural relay nodes on a basis of route information, acquiring a first and a second packets flowing between a server and a terminal apparatus, the second packet being transmitted on a basis of the first packet, calculating a first delay time on a basis of the first and the second packets, the first delay time relating to packet transmission between the server and the terminal apparatus, transmitting a third packet to the core node, receiving a response to the third packet from the core node, calculating a second delay time on a basis of the third packet and the response, the second delay time being a delay time of the core node, and calculating a third delay time being a delay time of an end node on a basis of the first and the second delay times.

Abstract: A monitoring apparatus for monitoring packet communication by a plurality of information processing apparatuses. The monitoring apparatus includes a receiving unit for receiving packets transmitted from the plurality of information processing apparatuses, a storage unit for storing a first identification value of a first packet and a first transmission source address of the first packet, and a processing unit for comparing a second identification value of a second packet with the first identification value of the first packet when a second transmission source address of the second packet matches the first transmission source address of the first packet to detect duplication of IP addresses when a difference between the first identification value and the second identification value exceeds a predetermined value.

Abstract: An abnormality locating apparatus locates an abnormal location in a network. An abnormal location judging part judges a normality or abnormality of a link based on a normality or abnormality of an observation flow, by acquiring information of links through which each observation flow passes, from a network route information storage that stores passing route information of observation flows passing through the links. A diagnosis accuracy judging part judges that an accuracy of judging the normality or abnormality of a connecting link connected to a first node deteriorates, by acquiring links connected to each relay node as connecting links from a relay node connecting link information storage that stores connecting link information of each relay node, and judging that a relay node having all connecting links thereof that are abnormal is the first node having all observation flows passing therethrough that are abnormal.

Abstract: A network fault detection apparatus, which detects L2 loops due to L3 bridge connections, is provided. A network fault detection apparatus acquires physical addresses corresponding to the network addresses of at least two nodes among the plurality of nodes constituting a network, and by detecting the existence of a plurality of physical addresses for network addresses of the two nodes, and detecting the existence of a physical address common to network addresses thereamong, detects an L2 loop caused by an L3 bridge connection, which induces a network fault.

Abstract: An abnormal point locating method includes: a link primary abnormality judgment procedure that acquires information on a link through which each observation flow passes, locates a link through which an observation flow observed at an observation point passes, and judges whether the located link is normal or abnormal based on the observation flow; and a link secondary abnormality judgment procedure that judges a probability of abnormality based on a result of the link primary abnormality judgment procedure by using a connection relationship as seen from each observation point.

Abstract: A band measurement method for measuring a band available for communication with a target device connected via a network includes: transmitting a first request having a first data size and requesting a response having a fixed size to the target device via the network; determining a first time between the transmitting of the first request and the receipt of the response upon receipt of the response; transmitting a second request having a second data size and requesting a response having the fixed size to the target device via the network; determining a second time between transmitting of the second request and the receipt of the response upon receipt of the response; and calculating a first communication band available for transmitting data to the target device by dividing the difference between the first and second data sizes by the difference between the first and second times.

Abstract: A network failure detecting method for detecting a failure of a network including a number of transferring devices by tracing data flow rates of the transferring devices based on physical topologies of the transferring devices for the network, composing a group of the transferring devices adjacent to one another, data flow rates of which have failed to be obtained, as one virtual transferring device; and replacing physical topologies of the group of the transferring devices adjacent to one another, data flow rates of which have failed to be obtained, with a physical topology of the composed virtual transferring device.

Abstract: A next sequence number, which is a sequence number that a next packet should have, is compared with the sequence number of a current packet, an identifier of a previous packet is compared with the identifier of the current packet, and a delay is judged to be a simple delay when the next sequence number matches the sequence number of the current packet and the identifier of the previous packet is followed by the identifier of the current packet. Or the delay is judged to be caused by a retransmission when the identifier of the previous packet is not followed by the identifier of the current packet.

Abstract: In a communication system, transmission/reception of data can be performed between end hosts connected to a relay switch in a subnet even in an improper connection at a L2 level in the relay switch in a communication. Communication failure due to a packet loop generated by the improper connection of the L2 level is recovered by wherein the packet loop is stopped by continuously transmitting long-size MAC packets longer than a packet generating the packet loop into the subnet, which have destinations as a broadcast MAC address or multicast MAC address.

Abstract: A device includes a storage unit that stores in a predetermined unit an identifier acquired from a packet transmitted from a transmitting device in association with a source address. The transmitting device receives from each terminal device connected communicatable via a network a packet including a source address, an identifier generated by adding a numerical value every time a packet is sent by the terminal device, and a session ID, and converts and transmits the source address. The transmitting device and the terminal device are connected to the device via a different network. The device also includes a determining unit that determines whether the identifier stored has monotonically increased; and a detector that detects a source indicated by a certain source address to be the transmitting device, if the determining unit determines that the identifier for the certain source address has not monotonically increased.

Abstract: A request-packet transmitting unit transmits a predetermined number of request packets having a non-unicast destination address that can be received by a target network including a network identified by a first network address, from a monitoring network identified by a second network address different from the first network address through a layer 3 relay device. A layer 2 loop detecting unit receives response packets corresponding to transmitted request packets through the layer 3 relay device, and detects a layer 2 loop in the target network based on number of received response packets and number of transmitted request packets.

Abstract: An information processing apparatus performs a communication in a communication network using packets. The communication network includes a relaying device having a function of acquiring traffic information of a packet that the relaying device relays. The information processing apparatus includes a transmission unit configured to transmit a packet to a specific node as a communication target; and a node position determining unit configured to determine a position of the specific node by acquiring the traffic information from the relaying device by which the packet is relayed in the communication network, analyzing the traffic information, and monitoring a flow of the packet with respect to the specific node.

Abstract: An information processing apparatus performs a communication in a communication network using packets. The communication network includes a relaying device having a function of acquiring traffic information of a packet that the relaying device relays. The information processing apparatus includes a transmission unit configured to transmit a packet to a specific node as a communication target; and a node position determining unit configured to determine a position of the specific node by acquiring the traffic information from the relaying device by which the packet is relayed in the communication network, analyzing the traffic information, and monitoring a flow of the packet with respect to the specific node.

Abstract: Disclosed is a communication control method for recovering communication failures caused by a packet loop that occurs as a result of L2-level misconnection at relay switches in a communication system where data transmission/reception is carried out between a plurality of end hosts connected to the relay switches within a subnet. The method includes the steps of consecutively sending packets each having, as its originator address, a MAC address other than an originator MAC address of an end host desired to be communicated making up the subnet; thereby stopping the packet loop; and then sending packet data using, as a destination MAC address, a MAC address of a destination end host.

Abstract: Only when a request formed of a plurality of request packets obtained by dividing the request is reconstructed, the request is transmitted to a survey target node that returns a response formed of a plurality of response packets obtained by dividing the response. When no response packet has been received at all from the survey target node, it is determined that any of the request packets has been discarded on a first route from a surveying node as a transmission source of the request to the survey target node. When one or more response packets have been received from the survey target node but the response cannot be reconstructed, it is determined that any of the response packets transmitted from the survey target node has been discarded on a second route from the survey target node to the surveying node as the transmission source of the request packets.

Abstract: A L2 loop failure location generated in any one of a plurality of search target apparatuses disposed in network is detected in a short time. A network failure location detecting apparatus executes the steps of broadcasting packets with a plurality of different source MAC addresses; acquiring statistical information that is information of a learning port of the plurality of different source MAC addresses learned by each of the plurality of search target apparatuses; finding whether the number of the learning ports of the plurality of different source MAC addresses is one or two from the acquired statistical information; and determining that the L2 loop failure location is the search target apparatus including two learning ports of the plurality of different source MAC addresses.

Abstract: A packet analysis apparatus analyzes content of communication obtained as a result of monitoring or capturing a packet passing through a network. The apparatus has a unit of acquiring source or destination address information from a network layer packet header. The apparatus has a unit of acquiring from the network layer packet header an identifier for which a value that increases monotonously with each sending for each source or destination address information is set. The apparatus has a unit of searching and acquiring an identifier corresponding to address information in a current packet from a storage part holding an identifier in a previous packet corresponding to source or destination address information. The apparatus has a unit of comparing the identifier in the previous packet acquired and the identifier in the current packet and determining that reordering occurs when the identifier in the current packet is smaller.