Of the myriad of OpenView modules offered by HP, Network Node Manager is the key monitoring and managing component.

It watches over devices, servers and applications, while other OpenView modules provide analysis services, produce additional reports and monitor specific environments, such as storage-area networks. Network Node Manager earned top honors in our test of more expensive midrange tools by accurately discovering our network, tracking device status, graphically displaying the network, alerting us to problems, automatically fixing problems, gathering statistics and processing incoming SNMP alerts from other monitoring products.

Network Node Manager's discovery feature took note of not only network devices, applications and servers but also virtual network services, such as VPNs.

Network Node Manager uses Management Information Base (MIB) data from several sources, including routers, switches, bridges and repeaters, to reset devices or inquire about their health. It captures some Layer 2 data, such as connections and node addresses, but for the most part it maps easier-to-relate-to Layer 3 details. The impressive list of predefined MIBs includes use and error percentages, total packets by category, retransmits, Cisco memory use and full-duplex utilization percentage.