The most accurate definition of a network management system that I have seen comes from a Cisco training document: "In some cases, it (network management) involves a solitary network consultant monitoring network activity with an outdated protocol analyzer. In other cases, network management involves a distributed database, auto polling of network devices, and high-end workstations generating real-time graphical views of network topology changes and traffic." - "Network Management Basics," Cisco Systems Inc. June 17, 1999.
Network management systems range from free, open-source tools such as OpenNMS to the pricey HP OpenView. They can be extremely powerful, complex and sophisticated. So it's important to choose the right tool for the job -- just as you would use a Cessna rather than a 747 to get you from Miami to the Bahamas, but you'd pick the 747 to go from New York to Los Angeles. Choosing a network management system hinges not only on price and user preference, but functionality as well. By looking at some of the more obvious features and determining from there how they fit into the scope of your network management plans, you can create a short list of tools.
Here are the key features that any network management system must have.
One simple interface: Everything that you need to see should be easily accessible. There should be no need to switch between screens to gather information. Look for a network management system that utilizes a Web-based interface that can be customized for different administrators.
Ability to set a baseline: To report errors and security-related events, the network management system needs to be able to recognize normal network operations through an established baseline. The ability to distinguish between normal and abnormal events cuts down on the false positive reports.
Reporting of actionable information: Simply stated, if your network management system can report an event to you, it should also have the tools to act upon that information. If your system flags a spike in abnormal traffic, that same screen should also have the information/tool to deal with it at well.
The next series of features that are listed are more specific to individual networks. Even smaller networks will employ some of these -- which ones are dependent upon the needs of the administrator.
Auto discovery: This discovers computers and components on your IT infrastructure without input from a person. It sends a packet to various devices on the network, and when a packet is acknowledged, an event in the management system is raised. Certain systems enhance this feature by visually mapping all of the components on the network or exporting/importing data to/from Excel spreadsheets or XML files.
Configuration import and analysis: Configuring and optimizing a network can take hundreds of hours, and one wrong setting can lose all of your previous work. An import and analysis feature lets you seamlessly integrate existing configurations and device policies into your network. It should also let you return your configuration to its original settings.
Policy-based configuration & deployment: An effective network management system should save you time, and this feature is designed to do just that. By writing one policy that can be applied to multiple devices, time and resources can be spent on other tasks. The ability to write policies from preexisting templates can also be useful. Once policies are in place, it's also helpful to be able to update or change them with little interruption. Some tools let you update a policy simultaneously on all the devices on a network that subscribe to that policy. The ability to set specific update times is important, as you can set update times to coincide with periods of low network traffic.
Policy-based auditing: The auditing process periodically confirms that all the configurations put into place meet the standards that have been set for the network. It also detects errors and inconsistencies across the network. A nice feature is the ability to send alerts to e-mail or cell phones.
Real-time data collection and reporting: The ability to continually collect data and report it to the network manager is essential in maintaining a healthy network. By proactively monitoring the network for performance-related issues and correlating these with other network events, you can pinpoint the source of network problems. These reports can be used to assess the impact network issues have on business processes so that the appropriate personnel can be notified. Additionally, the ability to collect data in real time can be used to pinpoint trends in network issues so you can take proactive measures to help alleviate network outages or decreased throughput.
Buy smart
When looking into the different network management systems, it's important to know exactly what you want this tool to accomplish. It's easy to go blindly into this purchase and select a vendor with the latest technology whose solution offers all the bells and whistles, only to regret your decision later. Just because Microsoft or IBM laud their products doesn't mean they're right for every shop. Buy what you need. Most products are scalable so you can always add features later.
Here are some good choices for different platforms:
HP OpenView Hewlett-Packard's OpenView repeatedly been heralded as the best network management system on the market. OpenView, which works in either a Windows or Unix environment, contains many of the features that a larger network would require. The tool set that is available for OpenView is probably the most comprehensive on the market. Its auto-discovery feature maps TCP/IP, IPX and Level 2 devices on both LAN and WAN devices by different categories, such as segment and status. Using event history and data analysis also allows for proactive network management, enabling administrators to take action prior to a problem occurring.
SolarWinds This is another popular tool that has earned itself a reputable market share. Like OpenView, SolarWinds boasts a large tool set with the ability to add tools should the need arise. Key features are the auto-discovery tool and the IP address management tools that help keep track of DCHP availability and usage details for individual addresses and their devices. Unlike OpenView, SolarWinds is designed to run solely in a Windows environment.
OpenNMS Not all network management systems have to come with a high price tag. Some have none at all. OpenNMS is an open-source network management system that offers an ample tool set for basic network management. The three key features of OpenNMS are polling, collecting performance data and event notification. Unlike the commercial products, OpenNMS doesn't come with support. Support packages, as well as training, can be purchased through OpenNMS. Currently, OpenNMS only runs on Solaris and Linux-based systems.
Jeffrey Orloff is a freelance writer and director of technology for an educational company in South Florida. He can be reached at jeff.orloff@gmail.com.