Network system and network flow tracing method

摘要

In a flow-based network such as an open flow network system, even when a network appliance such as NAT and NAPT for translating a packet header is passed through, a correspondence relation of two flows before and after the passing can be grasped to make it possible to trace the flow in end-to-end. Specifically, a packet is encapsulated in a switch (or in a controller requested from the switch). By encapsulating by using the same header as a current header, two kinds of headers before the translation and after the translation are attached to the packet after the packet phases through the network appliance.

主权项

1. A network system, comprising:
a switch having a function to process a reception packet based on a set entry of a flow table; a controller having a function to receive an inquiry of the packet from said switch, and to set the entry defining a rule and an operation to uniformly control packets to said flow table of said switch; an encapsulating module having a function to receive the packet from at least one of said switch and said controller and to encapsulate the packet by using a same header as a header of the packet; and a header translating unit having a function to receive a packet from said switch, to translate a first header data of a head of the received packet into a second header data thereof, and to transfer to another switch, wherein said encapsulating module has a function to receive a packet to which the first header data before translation and the second header data after the translation are given, when the encapsulated packet is transferred through said header translating unit, and to notify a set of the first header data before the translation and the second header data after the translation to said controller.