HP OpenView Network Node Manager 5.02 for Windows NT

Incorporate automatic network management

HP OpenView Network Node Manager (NNM) 5.02 for Windows NT brings the full power of HP's flagship network-management tool for UNIX to NT, along with a new user interface. (For information about updates to the software, see "Network Node Manager 6.0," page 114.) NNM, a member of HP's OpenView family of systems and network-management products, maps and monitors your network's IP and IPX addressable components (e.g., computers, routers, and Simple Network Management Protocol—SNMP—switches and hubs). The software's drill-down displays have color-coded status icons and customizable event-notification thresholds; thus, you can monitor your network easily.

Installation and Configuration
Installing NNM is easy. However, you might want to review the preinstallation file before you begin the installation. This file covers basics such as configuring the NNM server properly and using the same IP name for the Domain Name System (DNS) and your NNM server's IP configuration.

If you want to view and control your NNM installation from a remote location, you can install the software on other workstations in a console-only configuration. To efficiently manage distributed networks from a central location in larger enterprises, you can use the NNM servers as data-collection and data-forwarding engines. You can also distribute responsibility for network management among several people and NNM consoles.

Automatic Discovery
When you initialize NNM, the software automatically locates your network topology and components unless you turn off this option during installation. During my test, I used a 3Com SuperStack II Switch 1000, with twenty-four 10Base-T Ethernet ports and one 100 Base-TX Ethernet port. Approximately 30 systems connect to this Ethernet switch. However, NNM's initial automatic discovery added only four items to the map: the 3Com Ethernet switch, the subnet's default gateway, the NNM server, and the NNM server's NT domain controller.

Tracking down the reason for NNM's failure to discover the other systems was enlightening. When NNM discovered the switch, it located two interfaces with assigned IP addresses: the unit's primary address and a default Serial Line Internet Protocol (SLIP) address assigned to the serial port and used for the switch's initial configuration. NNM used the network address with the lower number as the switch's primary address. However, this address was also the serial port address. NNM attempted (and failed) to perform automatic discovery and submit SNMP queries through this interface. After I removed the unnecessary address from the switch and deleted the switch's icon from the map, NNM rediscovered the switch at the proper IP address and successfully discovered the network's topology. Screen 1 shows the default map that NNM generated. Each of the segment icons in the map drills down to a submap of the systems on that segment.

NNM discovers network devices and topology by querying the Address Resolution Protocol (ARP) cache of SNMP devices on its network segment. NNM uses an Internet Control Message Protocol (ICMP) echo (ping) to verify device addresses before adding them to the map. NNM then issues an SNMP query to find out if the devices are SNMP-capable. If they are, SNMP asks what kind of devices they are. Currently, NNM doesn't provide an option to perform a ping sweep through its IP subnets during initial automatic discovery. However, this option is under consideration for a future release.

Key Functions
NNM has several key functions. NNM provides significant extensibility (via third-party plug-in modules). The software can also automatically locate network components, lay out network topology (users can customize it by changing background images), and store SNMP Management Information Base (MIB) data (e.g., trend analyses). NNM can also set thresholds for event notification, program other actions to occur when a preset threshold triggers an event, and monitor MIB elements. You can view stored MIB elements graphically. NNM has a feature similar to NT Performance Monitor's realtime graphic display: NNM lets you monitor, graph, and view numeric MIB elements in realtime. NNM can also monitor, collect, and load numeric MIB elements that the monitored system supports. When you run the SNMP service on an NT system, NNM recognizes the availability of NT services. You can access the following utilities from the Tools menu for an NT system highlighted on the current map: Event Viewer, Registry Editor, NT Diagnostics, Performance Monitor, Server Manager, and User Manager. You can also access Microsoft's Systems Management Server (SMS) Properties and run SMS, if SMS Administrator is installed on the system.

SNMP
SNMP support provides NNM's real power. With SNMP support, NNM can do more than ping addresses on network systems. NNM can monitor, record, and generate events from numeric elements (e.g., interface packet counts, protocol statistics) that the network device maintains in its MIB.

You provide the information that NNM needs to access the MIB data in your SNMP devices. When you configure SNMP in a device, you configure community names (i.e., passwords that permit read-only or read-write access to data that the device maintains in its MIB). Frequently, SNMP devices default to a read-only community name of Public. NNM ships with Public configured as the global default community name in the SNMP configuration panel. If you establish a standard community name, you can configure it as a global default community name in NNM. NNM lets you configure community names by IPX network number, range of IP network numbers, or individual IP or IPX device addresses.

Using the community names you supply to gain access to your SNMP equipment, NNM queries and uses MIB data for network discovery. NNM also uses MIB data to monitor system health, generate events based on threshold values you set, and take other programmed actions you define to occur when the software generates an event.

During my test, I set up an event to monitor the operational status of several Ethernet ports in my switch. NNM generated a normal event log entry. (In this case, I also configured the event to use the NET SEND command to send a message to my user ID with information about the source of the alert.) On the Options menu, I clicked Data Collection & Thresholds: SNMP to configure events.

Defining Expressions
NNM lets you define expressions, which are values calculated from multiple MIB elements and used in the same way you would use individual MIB values as threshold values for event generation and for viewing or collecting data. Expressions improve your system's monitoring and data-collection capabilities. NNM predefines two expressions: Interface % Utilization and Disk % Utilization. Adding expressions isn't easy: You must use a text editor to modify the MIB expression configuration file and restart the NNM services that access that file. (I suspect this area is destined for enhancement in the future.)

Desktop Management
For desktop management, NNM supports two interfaces out of the box: Desktop Management Interface (DMI) and SNMP. NNM includes a remote DMI client for use on HP PC clients that support DMI 2.0 or HP-Remote DMI 1.1 and run Windows 3.x or Windows 95. You can query PCs that support DMI for configuration information that DMI provides, and you can monitor these PCs for DMI-based events.

Enterprise-Class Surveillance
You can deploy NNM as a powerful surveillance tool in your network war games. If you deploy NNM with other modules in the OpenView line, you'll have an enterprise-class systems-management solution.