The Simple Network Management Protocol (SNMP) is an application-layer (OSI Layer 7) protocol that enables network devices to retrieve telemetry (such as system load) and alerts from another system. This helps administrators closely monitor and manage their networking infrastructure in real time — keeping tabs on bandwidth consumption, performance, health, and overall system reliability.
SNMP has become ubiquitous across the IT landscape since its 1988 debut. As a result, most networking devices support the protocol via a specialized SNMP agent, which runs in the background to collect performance metrics. Admins can then make data-driven configuration updates as needed, either remotely or on-premises, while better understanding how the network responds to changing traffic conditions.
SNMP-powered networks often use a shared management station with the computing resources needed to perform network management. SNMP agents and managers rely on this station to transmit runtime data.
What makes the Simple Network Management Protocol (SNMP) useful?
Ultimately, SNMP gives network administrators greater oversight and control over the organization's network communication channels. This includes optimizing performance for critical network devices, boosting observability, and reducing both congestion and latency. SNMP also helps reduce the risk (or impact) of crashes.
Accordingly, SNMP can send alerts to administrators when abnormal behavior or crashes are detected. This accelerates the troubleshooting process.
A wide variety of device types also support SNMP, unlocking management functions across all areas of the business. These devices include:
Workstations
Printers
Firewalls
Modems and routers
Switches
Bridges
Load balancers
Storage devices
Internet of things (IoT) devices
Servers
By allowing this vast array of devices to communicate with each other, SNMP gives administrators the tools to build more robust, performant, and interconnected networks.
How does the Simple Network Management Protocol (SNMP) work?
SNMP-compatible devices send messages called practical data units (PDUs) between themselves to better understand system-wide activity and its impacts. These devices can track the flow of data across the network, monitor packet transmission, and log any errors. Admins can even use SNMP to monitor per-server request volumes or connection speeds.
SNMPv3 (the latest version of SNMP) supports five PDU message types:
SNMPGET – The system retrieves one or more runtime values from the base station.
GETNEXT – The system grabs the next value corresponding with a specific object identifier.
GETRESPONSE – The SNMP agent will return requested values of certain actions to the protocol manager. The base station can request either a complete status update, just a single data point, or anything in between from the agent.
SNMPTRAP – Devices send asynchronous alerts to the manager when a triggering network event happens, or when that device experiences a functional error. Trap commands can also retrieve status information proactively at set intervals to avoid surprise outages.
SNMPSET – The SNMP manager commands the SNMP agent to perform a specific task. These commands can alter how the device operates (including activating status indicator lights) and toggle other settings on or off, at will.
There are also multiple products that can import and interpret this SNMP data, making it even easier for administrators to shed the black-box element of networking.
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Does HAProxy support the Simple Network Management Protocol (SNMP)?
Yes! HAProxy Enterprise and HAProxy ALOHA support SNMPv2 and SNMPv3 to help administrators collect load balancer statistics from their clusters. This is achievable via the HAProxy configuration and your load balancer settings, which are easily accessible through HAProxy Fusion or the HAProxy ALOHA management interface.
To learn more about SNMP setup within HAProxy, check out our HAProxy Enterprise SNMP module documentation or our HAProxy ALOHA SNMP configuration documentation.