Abstract: In an apparatus, there are provided an IP transmitting and receiving unit for transmitting and receiving an IPv4 packet and an IPv6 packet; an IP header converting unit for performing a mutual conversion of the IPv4 packet and the IPv6 packet by an IP header conversion; a DNS substituting unit for receiving a domain information capturing request sent from an IPv4 terminal or an IPv6 terminal and substituting its process; an IPv4 address capturing unit for capturing an IPv4 address from a DHCP server; and an IP address conversion information holding unit for holding an IPv6 address of the IPv6 terminal and the IPv4 address captured by the IPv4 address capturing unit in correspondence to each other. Thus, a communication with the IPv4 terminal can be executed without preliminarily fixedly allocating the IPv4 address to the IPv6 terminal.

Abstract: A translator for coupling a first IPv4 network and a second IPv6 network having different addressing architectures for IP addresses so as not to exhaust the IP addresses of one of the two networks, a network system using the translator, and a network coupling method. When a packet is transferred from the IPv6 network to the IPv4 network, the translator assigns any of previously prepared IPv4 addresses to an IPv6 address stored in a source storing field of the IPv6 packet. The assigned address is stored in a source storing field of an IPv4 packet. A packet translation unit assigns the foregoing IPv6 address to an IPv4 address stored in a destination storing field of the IPv4 packet, when a packet is transferred from the IPv4 network to the IPv6 network, and stores this address in a destination storing field of the IPv6 packet.

Abstract: In an apparatus, there are provided an IP transmitting and receiving unit for transmitting and receiving an IPv4 packet and an IPv6 packet; an IP header converting unit for performing a mutual conversion of the IPv4 packet and the IPv6 packet by an IP header conversion; a DNS substituting unit for receiving a domain information capturing request sent from an IPv4 terminal or an IPv6 terminal and substituting its process; an IPv4 address capturing unit for capturing an IPv4 address from a DHCP server; and an IP address conversion information holding unit for holding an IPv6 address of the IPv6 terminal and the IPv4 address captured by the IPv4 address capturing unit in correspondence to each other. Thus, a communication with the IPv4 terminal can be executed without preliminarily fixedly allocating the IPv4 address to the IPv6 terminal.

Abstract: A network switch including a plurality of switches are mutually connected operable as one switch stack with maintenance operation to be logically performed, and wherein the switch stack can be constructed by connecting a plurality of switches having different enclosing conditions. A stackable switch operable under one of the following two operation references of switches: only one or a plurality of switches having the largest enclosing condition play as a master and the backup and if communication cannot be made or backup and the switch having the largest enclosing condition serving as an alternative switch does not exist, it is regarded that the switch stack entered an operation incapable state; and the switch operates in accordance with the smallest enclosing condition among all of the switches constructing the stack.

Abstract: In an apparatus, there are provided an IP transmitting and receiving unit for transmitting and receiving an IPv4 packet and an IPv6 packet; an IP header converting unit for performing a mutual conversion of the IPv4 packet and the IPv6 packet by an IP header conversion; a DNS substituting unit for receiving a domain information capturing request sent from an IPv4 terminal or an IPv6 terminal and substituting its process; an IPv4 address capturing unit for capturing an IPv4 address from a DHCP server; and an IP address conversion information holding unit for holding an IPv6 address of the IPv6 terminal and the IPv4 address captured by the IPv4 address capturing unit in correspondence to each other. Thus, a communication with the IPv4 terminal can be executed without preliminarily fixedly allocating the IPv4 address to the IPv6 terminal.

Abstract: A translator for coupling a first IPv4 network and a second IPv6 network having different addressing architectures for IP addresses so as not to exhaust the IP addresses of one of the two networks, a network system using the translator, and a network coupling method. When a packet is transferred from the IPv6 network to the IPv4 network, the translator assigns any of previously prepared IPv4 addresses to an IPv6 address stored in a source storing field of the IPv6 packet. The assigned address is stored in a source storing field of an IPv4 packet. A packet translation unit assigns the foregoing IPv6 address to an IPv4 address stored in a destination storing field of the IPv4 packet, when a packet is transferred from the IPv4 network to the IPv6 network, and stores this address in a destination storing field of the IPv6 packet.

Abstract: A translator for coupling a first IPv4 network and a second IPv6 network having different addressing architectures for IP addresses so as not to exhaust the IP addresses of one of the two networks, a network system using the translator, and a network coupling method. When a packet is transferred from the IPv6 network to the IPv4 network, the translator assigns any of previously prepared IPv4 addresses to an IPv6 address stored in a source storing field of the IPv6 packet. The assigned address is stored in a source storing field of an IPv4 packet. A packet translation unit assigns the foregoing IPv6 address to an IPv4 address stored in a destination storing field of the IPv4 packet, when a packet is transferred from the IPv4 network to the IPv6 network, and stores this address in a destination storing field of the IPv6 packet.

Abstract: A packet communication method and a packet communication system capable of making an IPv4-compatible application operating on an information processing apparatus communicate with another information processing apparatus connected to an IPv6 network without using an address translation router. In the information processing apparatus connected to the IPv6 network, an IPv4-to-IPv6 protocol conversion control function is incorporated in a LAN driver. A protocol conversion control module receives an IPv4 packet from a protocol control module. When a send destination IPv4 address contained in a header of the packet is registered in an address translation table incorporated in the protocol conversion control module, an IPv6 address is generated to be sent onto a LAN. Unless the send destination IPv4 address contained in the packet header is registered in the address translation table incorporated in the protocol conversion control module, the IPv4 packet as received is intactly sent onto the LAN.

Abstract: A communications apparatus for converting an IPv4 multicast packet transmit from an IPv4 terminal into an IPv6 multicast packet and transmitting the converted IPv6 multicast packet to one of a plurality of IPv6 networks. The communications apparatus has information indicating to which IPv6 network the IPv4 multicast packet to undergo conversion processing is to be transmitted. The communications apparatus then converts the received IPv4 multicast packet into an multicast packet and transmits the converted IPv6 multicast packet to an IPv6 network where it is required to be sent.

Abstract: In an apparatus, there are provided an IP transmitting and receiving unit for transmitting and receiving an IPv4 packet and an IPv6 packet; an IP header converting unit for performing a mutual conversion of the IPv4 packet and the IPv6 packet by an IP header conversion; a DNS substituting unit for receiving a domain information capturing request sent from an IPv4 terminal or an IPv6 terminal and substituting its process; an IPv4 address capturing unit for capturing an IPv4 address from a DHCP server; and an IP address conversion information holding unit for holding an IPv6 address of the IPv6 terminal and the IPv4 address captured by the IPv4 address capturing unit in correspondence to each other. Thus, a communication with the IPv4 terminal can be executed without preliminarily fixedly allocating the IPv4 address to the IPv6 terminal.

Abstract: In an apparatus, there are provided an IP transmitting and receiving unit for transmitting and receiving an IPv4 packet and an IPv6 packet; an IP header converting unit for performing a mutual conversion of the IPv4 packet and the IPv6 packet by an IP header conversion; a DNS substituting unit for receiving a domain information capturing request sent from an IPv4 terminal or an IPv6 terminal and substituting its process; an IPv4 address capturing unit for capturing an IPv4 address from a DHCP server; and an IP address conversion information holding unit for holding an IPv6 address of the IPv6 terminal and the IPv4 address captured by the IPv4 address capturing unit in correspondence to each other. Thus, a communication with the IPv4 terminal can be executed without preliminarily fixedly allocating the IPv4 address to the IPv6 terminal.

Abstract: A packet communication method and a packet communication system capable of making an IPv4-compatible application operating on an information processing apparatus communicate with another information processing apparatus connected to an IPv6 network without using an address translation router. In the information processing apparatus connected to the IPv6 network, an IPv4-to-IPv6 protocol conversion control function is incorporated in a LAN driver. A protocol conversion control module receives an IPv4 packet from a protocol control module. When a send destination IPv4 address contained in a header of the packet is registered in an address translation table incorporated in the protocol conversion control module, an IPv6 address is generated to be sent onto a LAN. Unless the send destination IPv4 address contained in the packet header is registered in the address translation table incorporated in the protocol conversion control module, the IPv4 packet as received is intactly sent onto the LAN.

Abstract: A packet forwarding device equipped with a statistics collection device and statistics collection method for high speed ports at a low cost while maintaining the required statistical accuracy for each flow. In order to collect a statistic flow with the required accurate statistic information this device contains a high speed flow table, a flow table made up of many flow entries, a search decision table to decide whether to search the high speed flow table or large volume flow table; and the table to be searched is decided when a packet is received. The accuracy of the statistic information for the flow requiring accurate statistic information is guaranteed by the high speed flow table. Further by setting the large volume flow table and sampling rate as needed, statistic information for many flow entries can be collected with a sufficient flow of sampled statistic information, without lowering packet forwarding performance.

Abstract: The present invention provides a technology including, for example, a packet relay processing section to carry out packet relay, a packet sampling section to carry out packet sampling, a flow statistics counting section to take statistics of each flow, and a flow statistics generating section to generate a NetFlow export datagram, wherein the flow statistics counting section collectively counts the number of the packets or bytes received per unit time when the number does not exceed a threshold value and individually counts the number for each flow when the number exceeds the threshold value, and thereby a flow of abnormal traffic which is suspected to be DoS attack is efficiently detected with small amounts of resources (mainly memories).

Abstract: A packet communication method and a packet communication system capable of making an IPv4-compatible application operating on an information processing apparatus communicate with another information processing apparatus connected to an IPv6 network without using an address translation router. In the information processing apparatus connected to the IPv6 network, an IPv4-to-IPv6 protocol conversion control function is incorporated in a LAN driver. A protocol conversion control module receives an IPv4 packet from a protocol control module. When a send destination IPv4 address contained in a header of the packet is registered in an address translation table incorporated in the protocol conversion control module, an IPv6 address is generated to be sent onto a LAN. Unless the send destination IPv4 address contained in the packet header is registered in the address translation table incorporated in the protocol conversion control module, the IPv4 packet as received is intactly sent onto the LAN.

Abstract: A translator for coupling a first IPv4 network and a second IPv6 network having different addressing architectures for IP addresses so as not to exhaust the IP addresses of one of the two networks, a network system using the translator, and a network coupling method. When a packet is transferred from the IPv6 network to the IPv4 network, the translator assigns any of previously prepared IPv4 addresses to an IPv6 address stored in a source storing field of the IPv6 packet. The assigned address is stored in a source storing field of an IPv4 packet. A packet translation unit assigns the foregoing IPv6 address to an IPv4 address stored in a destination storing field of the IPv4 packet, when a packet is transferred from the IPv4 network to the IPv6 network, and stores this address in a destination storing field of the IPv6 packet.

Abstract: A translator for coupling a first IPv4 network and a second IPv6 network having different addressing architectures for IP addresses so as not to exhaust the IP addresses of one of the two networks, a network system using the translator, and a network coupling method. When a packet is transferred from the IPv6 network to the IPv4 network, the translator assigns any of previously prepared IPv4 addresses to an IPv6 address stored in a source storing field of the IPv6 packet. The assigned address is stored in a source storing field of an IPv4 packet. A packet translation unit assigns the foregoing IPv6 address to an IPv4 address stored in a destination storing field of the IPv4 packet, when a packet is transferred from the IPv4 network to the IPv6 network, and stores this address in a destination storing field of the IPv6 packet.

Abstract: A multicast communication method for allowing a communication control apparatus for communicating in accordance with IPv4 to communicate with a communication control apparatus for communicating in accordance with IPv6. This method includes the steps of: when an IPv4 multicast packet is inputted, discriminating that this packet is a data packet on the basis of an IPv4 header; when it is determined that the packet is the data packet, converting the IPv4 header of the IPv4 multicast packet into an IPv6 header; generating an IPv6 multicast packet; and outputting the generated IPv6 multicast packet to a IPv6 network.

Abstract: A communications apparatus for converting an IPv4 multicast packet transmit form an IPv4 terminal into an IPv6 multicast packet and transmitting the converted IPv6 multicast packet to one of a plurality of IPv6 networks. The communications apparatus has information indicating to which IPv6 network the IPv4 multicast packet to undergo conversion processing is to be transmitted. The communications apparatus then converts the received IPv4 multicast packet into an IPv6 multicast packet and transmits the converted IPv6 multicast packet to an IPv6 network where it is required to be sent.

Abstract: A communications apparatus for converting an IPv4 multicast packet transmit from an IPv4 terminal into an IPv6 multicast packet and transmitting the converted IPv6 multicast packet to one of a plurality of IPv6 networks. The communications apparatus has information indicating to which IPv6 network the IPv4 multicast packet to undergo conversion processing is to be transmitted. The communications apparatus then converts the received IPv4 multicast packet into an multicast packet and transmits the converted IPv6 multicast packet to an IPv6 network where it is required to be sent.