What is SNMP

One of the network management protocols that is really helpful and useable is SNMP. This standard protocol can manage devices on ip networks and modify information to change device behavior.

Devices that normally support SNMP include cable modems, routers, network switches, servers, firewall, CCTV cameras, workstations and printers and more. In this article, we will cover the basics of SNMP protocol and its role in network management, explore the different various of SNMP and reveal how you can use SNMP securely and effectively on your network.

What is SNMP:

SNMP is short form of simple network management protocol that widely used in network management for network monitoring. This protocol exposes management data in the form of variables on the managed systems organized in a MIB which describes the system status and configuration.

It’s an application layer protocol included in the internet protocol suite, a set of the most commonly used communication protocols online. Today, it’s one of the most widely accepted protocols for network monitoring. SNMP is a powerful tool that facilitates the sharing of information among various devices on a network, regardless of their hardware or software.

For answering to question of “What is Simple Network Management Protocol?” we can say to maintain constant uptime and high-bandwidth network operations, network administrators control network devices and assign interfaces and ports. By strategically assigning the optimal ports that devices can use to communicate, IT teams make it easier for traffic to flow through the network more freely. Otherwise, there will be data “log jams” that result in latency and poor performance. SNMP device monitoring is a significant element of this process.

SNMP enables administrators to monitor how devices are performing and make changes to network devices so that data moves through the network more efficiently. But first, to use SNMP monitoring, the SNMP agent implemented on a network device has to be configured to send monitoring data to an SNMP manager (more on this below). Once done, admins can concentrate on making adjustments to optimize network performance.

How does SNMP protocol work:

Your network experiences different types of traffic during the day as users browse the web, transfer files, download files, and engage in other activities that involve sending and receiving data. SNMP communicates with your network to get details about each network device’s activities. For example, it monitors the number of packets, bytes, and errors sent by your websites, as well as the number of hits it receives per day.

SNMP also communicates with devices on your network by sending queries or messages known as protocol data units (PDUs) to each device. Network administrators can track almost any data value they specify using these messages. This enables them to pull data from each device to see how it is performing.

SNMP works by sending protocol data units, also known as SNMP GET requests, to network devices that respond to SNMP. All these communications are tracked, and network monitoring tools use GET requests to fetch data from SNMP. Traffic flows into your network from different sources. Simple Network Management Protocol communicates with the whole network and the devices in it.

SNMP is preconfigured on devices, and once the protocol is enabled, the devices will store their performance stats. Each network server will have multiple management information base (MIB) files. The device MIB files are queried to fetch the monitoring data. The working of SNMP revolves around its components, with each component contributing to the management of resources.

What is SNMP port and port number:

An SNMP port is an SNMP communication endpoint that identifies SNMP data transfers. SNMP uses both port 161 and port 162 for sending commands and messages. SNMP protocol managers communicate with SNMP agents through designated SNMP ports. SNMP message transfers happen via the User Datagram Protocol (UDP). The Transport Layer Security (TLS) or Datagram Transport Layer Security (DTLS) protocols are sometimes used.

There is a table of port number of each protocol uses for specific processes:

Why is SNMP monitoring tools necessary?

without SNMP monitoring, administrators would struggle to control and monitor devices on their networks.

Based on the information supplied by SNMP protocol, administrators can monitor the performance and availability of SNMP network devices and identify problems to keep their network healthy. IT teams can therefore get a thorough picture of their entire network environment by using the appropriate SNMP monitoring tool. Additionally, SNMP monitoring software presents data in formats that are easy to understand and includes presentations about how to improve network performance. Without SNMP monitoring tools, the process of gathering and organizing device data would take too long and waste IT team members’ time.

Read More: What is DHCP

Network admins manage the devices in a network and allocate or release ports, interfaces and more to ensure continuous uptime and bandwidth-hog-free network operations. Closely monitoring SNMP devices is a significant part of this. SNMP monitoring requires an admin to configure the SNMP agent to send the monitoring data to an SNMP manager. Since the network management tool takes care of monitoring, admins can focus on performing corrective measures.

Based on the insights provided by these tools, admins can track the availability and performance of SNMP network devices and pinpoint issues to maintain their network’s health. The ideal SNMP monitoring tool monitors different versions of the protocol to help IT admins get a complete picture of their network environment. SNMP monitoring software also shows the captured data in intuitive formats, like dashboards and graphs.

Different types of SNMP:

• SNMP manager: referred to as a network management station (NMS), the SNMP manager watches over the SNMP network. It communicates with network devices via the SNMP agents and operates on a network host, which is a computer on a network. It then sends queries to agents, receives their responses, configures their variables, and records events that come from them.
• Managed devices: A managed device is an SNMP-capable network component the SNMP manager controls. Typically, these are printers, wireless devices, routers or switches.
• SNMP agent: An SNMP agent is a piece of software that reacts to SNMP requests by providing information about a network device’s status and metrics. This gives SNMP agents the most significant role in the SNMP ecosystem. They gather, store, and send monitoring data from SNMP network devices that are nearby and connected to the agent. When a query is made, data is sent to the selected SNMP manager—and this is what an administrator can read and analyze.
• Management information database (MIB): A structure called an SNMP MIB outlines how information is exchanged in an SNMP system. Every SNMP agent has a database with information that outlines the specifications of the devices it controls. An SNMP manager gathers data for performance management, fault management, and data storage using SNMP. The MIB stores data acquired from each device on the network and serves as a shared database for the agent and the SNMP manager. To make network building, testing, deployment, and operations easier, the SNMP system uses MIBs to save information as text files in a predefined format. In this way, MIB editors, network management tools, SNMP agent builders, and network simulation tools can all understand the data within the MIB.
• SNMP OID: OID stands for object identifier and it provides an address that the system can use to identify the devices administrators are managing and monitoring.

It divides to two categories;

1. Scaler: objects that are defined by a single object instance are called scalars. This means there can only be one instance of the object.
2. Tabular: grouped in MIB tables, these objects are defined by numerous linked object instances. OIDs are arranged hierarchically in MIBs. All of the manageable elements of each device are grouped in this hierarchical structure, making them easier for administrators to visualize.

MIBs organize OIDs hierarchically, represented by a tree structure with individual variable identifiers for each OID. This tree structure contains all the manageable features of all the products arranged in it. Each branch of this tree has a number and a name, and each point is named after the complete path—from the top of the tree down—that leads to that point.

Read more: What is QoS

Three versions of SNMP:

Three significant versions of SNMP protocol have been developed and deployed. SNMPv1 is the original version of the protocol. More recent versions, SNMPv2c and SNMPv3, feature improvements in performance, flexibility and security.

• SNMPv1:

SNMP version 1 was the first implementation of SNMP, and it supports 32-bit counters, which limit its ability to secure a system, specifically due to the relatively slow rate at which it can process information—32 bits at a time. It uses clear-text community strings, which work like passwords or user IDs to allow access to device data. However, this kind of authentication is less secure than what the newer versions use.

• SNMPv2c:

This revised version includes enhanced protocol packet types, transport mappings, and MIB structure elements. But it also uses the existing SNMPv1 administration structure, which is “community-based,” hence the version name SNMPv2c. It is defined in RFC 1901, RFC 1905, and RFC 1906.

• SNMPv3:

SNMPv3 supports the remote configuration of SNMP entities. It also adds both encryption and authentication, which can be used together or separately, making this the most secure version yet. RFCs for SNMPv3 are RFC 1905, RFC 1906, RFC 2571, RFC 2572, RFC 2574, and RFC 2575.

What are SNMP Commands:

SNMP uses five basic messages to allow the SNMP manager and SNMP agent to communicate:

• Trap: The SNMPTRAP command is a common manner for devices to send alerts. These are asynchronous messages sent to the manager by an agent when something needs to be reported. A storage appliance, for example, might send a trap to the manager when it loses access to a drive. Other examples include a power-up situation or high-traffic notification that should be evaluated. But SNMP managers don’t have to sit around waiting for agents to send a message. They may prefer to ask for data proactively. This ensures devices are still active and functioning properly. Without a proactive check you may not know if a quiet device is offline or simply doesn’t have anything to report.
• Get: The SNMPGET command retrieves one or more values from the MIB (management information base).
• Get Next: The GETNEXT command retrieves the next corresponding value of the OID (object identifier) in the MIB tree.
• Get Response: The GETRESPONSE command is used by the agent to send back the values of actions requested by the SNMP manager. If a manager wants to ask an agent for data with a get message, the agent will send back a get-response. The manager might only need that one piece of data, or it can then send a get-next message (and then another, and another) to request a full status update.
• Set: The SNMPSET command is used by the SNMP manager to tell an agent to take action. Some agents control relay outputs that can be toggled. Others have beacon lights, backup systems, thermostats, and other settings that can be changed with a set command.

Read more: What is Cisco Switch

Two Types of SNMP Configurations:

SNMP uses read and read-write community strings to share information. Both can be configured to allow public access or set to prevent unauthorized changes.

Read: The read strings can be read by any application or device that can speak SNMP.

Read-Write: The read-write SNMP string can allow a user to set or manipulate values such as a device’s settings.

conclusion:

we hope this article has been useful, if you want to know about other protocols about network equipment such as cisco switch, hp server and other devices click on Atech blog and read our posts. in this blog, we try to explain SNMP protocol, its work, its various, its versions and more details.