Today measuring traffic is an essential tool for controlling and engineering communication networks and must provide useful information about flow states for network administrator. In this paper we present a measurement system for monitoring IP networks based on IPFIX (IP Flow Information eXport Protocol). This passive monitoring system can provide network operators with detailed information about the traffic traversing a network. Packet traces can provide information about the performance experienced by flows and other characteristics of the traffic, such as packet sizes, packet loss, one way delay and delay variation. We used the well-known database MySQL to store and retrieve data. The meter/exporter and collector process were implemented in the Linux operating system environment. The proposed monitoring system was tested in a campus network.