What Is Network Monitoring?

Network monitoring refers to the oversight of a computer network using specialized management software tools. Network monitoring systems ensure the availability and overall performance of computers and network services. Network admins monitor access, routers, slow or failing components, firewalls, core switches, client systems, and server performance—among other network data. Network monitoring systems are typically employed on large-scale corporate and university IT networks.

Key Features in Network Monitoring

A network monitoring system detects and reports failures of devices or connections. It measures the CPU utilization of hosts, the network bandwidth utilization of links, and other aspects of the operation. It often sends messages—sometimes called watchdog messages—over the network to each host to verify if it is responsive to requests.

When failures, unacceptably slow response, or other unexpected behavior is detected, these systems send additional messages called alerts to designated locations to notify system administrators. The location may be a management server, an email address, or a phone number.

Network Monitoring Software Tools

The ping program is one example of a basic network monitoring program. Ping is a software tool available on most computers that send Internet Protocol test messages between two hosts. Anyone on the network can run basic ping tests to verify that the connection between two computers is working and also to measure the current connection performance.

While ping is useful in some situations, some networks require more sophisticated monitoring systems. These systems may be software programs that are designed for use by professional administrators of large computer networks.

One type of network monitoring system is designed to monitor the availability of web servers. For large enterprises that use a pool of web servers that are distributed worldwide, these systems detect problems at any location.

Simple Network Management Protocol

Simple Network Management Protocol is a popular management protocol that includes network monitoring software. SNMP is the most widely used network monitoring and management protocol. It includes:

• The devices in the network that is being monitored.
• Agent software on the monitored devices.
• A network management system, which is a toolset on a server that monitors each device on a network and communicates information about those devices to an IT administrator. 

Administrators use SNMP to monitor and manage aspects of their networks by:

• Gathering information on how much bandwidth is being used on the network.
• Active polling network devices to ask for a status at specified intervals.
• Notifying the admin by text message of a device failure.
• Collecting error reports, which can be used for troubleshooting.
• Emailing an alert when the server reaches a specified low disk space level.

SNMP v3 is the current version. It should be used because it contains security features that were missing in versions 1 and 2.