Patent ID: 7792133
Filing Date: 2010-09-07
Classification: H04L

Abstract:
1. A packet relay device which relays a packet, comprising a plurality of network processors, wherein on a condition that an interface (IF), as an output destination determined for a session to which a packet received from an external network, is associated with another network processor, the plurality of network processors each transmit said packet and IF specifying information which specifies said IF to said other network processor, wherein the packet comprises a fragment Internet Protocol (IP) packet, wherein each of the plurality of network processors includes an IP fragmentation table having an entry in which a fragment offset and a fragment IF specifying information of an IF to be an output destination of the fragment IP packet is registered that correlates with a transmission source IP address and a destination IP address of the fragment IP packet, wherein, when one of the plurality of network processors receives the fragment IP packet through an external network, the one of the plurality of network processors searches the IP fragmentation table, wherein, when there exists an entry in the IP fragmentation table in which a same transmission source IP address, destination IP address, and fragment offset as a transmission source IP address, a destination IP address, and a fragment offset of the fragment IP packet are registered, the one of the plurality of network processors obtains the IF specifying information in the entry, and updates the fragment offset in the entry, based on a packet length of the fragment IP packet, and wherein, when there exists no relevant entry in the IP fragmentation table, the one of the plurality of network processors searches for the IF specifying information of an IF to be an output destination of the fragment IP packet, registers the searched IF specifying information, and adds a new entry including the transmission source IP address, the destination IP address, and the fragment offset in the fragment IP packet.