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What is SNMP?

 

In our industry, there’s a lot of terminology tossed around. Here at KMC, we’ve decided to periodically choose a topic and take a closer look to help learn the basics. In this post, we dig into SNMP.

SNMP, which stands for “Simple Network Management Protocol,” is used to monitor and configure devices on a network, as well as receive alerts directly from those devices.There are 3 main components to the SNMP protocol:

SNMP

  1. The SNMP Manager
  2. The SNMP Agent
  3. The MIB


First let’s talk about the SNMP manager. The SNMP manager or management system, is a separate computer or server that is responsible for communicating with the SNMP agent devices on the network.The key functions of the manager are to: 

  • Query the agents
  • Get responses from the agents
  • Set variables in the agents
  • Acknowledge one-way notifications from agents 


For KMC Controls, our IoT Platform, KMC Commander, acts as an SNMP Manager, gathering data points from devices, as well as triggering actions.

The second piece of this protocol is an SNMP Agent, a device on a network that you want to monitor. This includes IT components such as:

  • Routers
  • Data Servers
  • Workstations
  • Printers
  • Uninterruptable Power Supplies 


Many other IT-centric devicesThe third component lies inside the SNMP agent. The MIB, or Management Information Database, is a database in a device containing data points specific to that device, which can be provided to or configured by a Manager. These data points are called Object Identifiers, or OIDs. Examples of OIDs include:

  • Network status
  • Run time
  • Disk RPMs
  • Device temperatures
  • CPU and power usage
  • Other device-specific variables


The MIB file should be provided by the device manufacturer and uploaded to the Manager in order to decipher received data. The MIB does not come natively from the agent itself.

SNMP has three common versions: Version 1, 2C, and 3.

Version 1 is the simplest and oldest, dating back to the late 1980s. While easy to set up, Version 1 has little to no security. This is because of ‘community strings,’ which act like a password to access a device. If a request from the SNMP manager has the correct community string, the devices will respond to the query for information. If the string is wrong, the device will not respond. Most SNMP Version 1 and version 2C equipment come preprogramed with community strings set as “public” or “private”. It is recommended that network managers change all the strings to custom values.

Version 2C is the most common version of SNMP used today. It is similar to Version 1, but with additional features, such the ability to gather the same amount of data with less queries. On the technical side, Version 2C gives you more flexibility and is recommended to use over Version 1.

Version 3 is the newest form of the protocol. It adds many security features lacking in the previous versions. This includes encryption and user name and password authentication, as well as data validation. Version 3 is more complex to setup, but if you require security this is recommended.

To learn more about the protocol, click here.

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