Simple Network Management Protocol: The Basics
Network monitors need to examine several different types of devices in order to accurately determine network performance. Every type of device operates in a different way, and each one has specific ways of transmitting information. Thus, without a common protocol to follow, network performance monitors (NPMs) would have trouble gathering all the information they need.
Thankfully, to help NPMs keep track of everything, most devices comply with Simple Network Management Protocol (SNMP). This protocol provides a standard way to monitor hardware and software for the monitoring agent to analyze. SNMP allows for network monitors to gather data from every device on the network and deal with it from one centralized application. Below, we’ll explain what exactly SNMP is and the benefits it provides for NPMs.
How does SNMP work?
SNMP requires only two components to work: managers and agents. Managers are software and applications that collect information from your network. Agents are programs that reside in devices that gather information and send it to the manager. Managers can signal agents to transmit specific data using a call-and-response system. Managers can also send configuration instructions to agents by using a “set” command. Another manager feature is polling, which asks agents to provide status and condition updates on a routine basis. In addition, agents can send “traps” to the manager whenever a significant event (such as a device failure) occurs in order to alert the user.
Objects and MIBs
Diving further into the functionality of SNMP, two concepts that relate to the key workings of the protocol are objects and MIBs. Objects are variables and metrics that an SNMP manager can ask its agents about – for example, the number of network services on a server. SNMP identifies objects agents can report on with an Object Identifier (OID). An OID is a hierarchical data tree that lists every object that SNMP recognizes.
Management information bases (MIBs) are similar in concept, listing each device on the network and every object that the device that it can interact with. A MIB is a database that allows the manager to keep track of object status by classifying every object the manager should recognize. Using OIDs and MIBs, SNMP devices can communicate to each other in a common language. This allows your NPM to easily translate the status reports each device gives and display them for the user.
The advantages of SNMP
Odds are most, if not all, of the devices on your network are SNMP compatible. However, if you haven’t already configured them for SNMP, it’s most likely not yet enabled on them. SNMP requires that you manually turn it on for each device. This is to eliminate the security risk of accidentally running an insecure SNMP protocol.
There are plenty of reasons to enable SNMP, however, including:
- Standardized device monitoring, eliminating the need for complex monitoring configurations
- Vendorless monitoring (meaning devices from any manufacturer are recognized)
- Automatic parameter monitoring
- Real-time status updates
- Centralized management location – all the data can be sent to and processed at one area on your network
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