Background: Know: Recognize:

Anticipates: Simple Network Management Protocol (SNMP), root cause analysis

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NM=the manual stuff?Edit

1. What is Network Management

The need for Network Management (NM) arises from the difficulty, imprecision or complexity that is beyond the capability of automated systems. Unfortunately, NM covers a broad range of networks and activities that no short definition can capture the task well. Thus, rather than give a short, precise definition of NM, it is much more straightforward to define NM intuitively : NM encompasses tasks associated with planning, deploying, configuring, operating, monitoring, tuning, repairing and changing computer networks. A common way of characterizing network management functions is FCAPS-Fault, Configuration, Accounting, Performance and Security.

2. The Goal of Network Management

The goal of network management is to ensure that the users of network are provided IT services with a quality of service that they expect. Toward meeting this goal, the management should establish a policy to either formally or informally contract an SLA with users.

From a business administration point of view, network management involves strategic and tactical planning of engineering, operations, and maintenance of network and network services for current and future needs at minimum overall cost. There needs to be a well-established interaction between the various groups performing these functions.

3. The motivation for automation

From a network operator’s point of view, current network management is labor-intensive, requires in-house expertise, and because humans are involved, is prone to errors and slow.

Human error has become extremely important because the complexity of management tasks continues to increase. For example, consider a firewall configuration that includes hundreds of individual rules. In addition to errors that arise from mistyping configurations, errors can occur because the rule set is too large for a human to remember and understand.

Human also tend to introduce consistency errors – when a large set of devices is configured manually, chances are high that the configurations will be inconsistent.

In addition to eliminating inconsistencies and human error, automation can reduce economic impact by reducing the downtime needed for upgrades and other changes. For example, an intrusion detection system can automatically modify firewall rules to stop a problem that is in process. Finally, automated network management will increase sales because automation will allow customers to create large, more complex networks.

4. Why does NM usually involve human intervention

Although tools have been devised that automate some aspects of network management, a comprehensive and automated network management system will not be possible. The reason is fundamental: a lack of abstractions and principles. Therefore, automation has not occurred and human intervention is usually involved. For example, to configure firewalls for a site that has multiple Internet connections, a manager need to manually configure the firewall rules in each of the routers that has an Internet connection.

5. Technologies in NM

Like a DNS server, a server for the DHCP can operate for extended periods without being reconfigured. The configuration is only changed when IP subnet addresses are reassigned.

DHCP server is used to provide IP addresses and other information needed for communication to a host automatically (usually when the host boots).

A DHCP server can provide optional configuration parameters to the client. RFC 2132 describes the available DHCP options.

e.g. IBM Network Manager

It is automatic network discovery and topology-based management software designed to help organizations improve network visibility and drive reliability and performance. Real-time root-cause analysis helps operations personnel quickly identify the source of network faults and speed problem resolution.

e.g. Cisco Info Center OMNIbus and Network Manager

It is another very famous RCA software. Network faults are visualized with real-time analysis of the root cause, reducing the time needed to troubleshoot network issues. Consequential fault events are automatically correlated to the root-cause fault event in real time.

Above all, we know that NM is different from the manual stuff. And more differences between them are pointed out in Man vs machine.


D. Comer, Automated Network Management Systems: Current and Future Capabilities, Pearson, 2007, p25-35.