---
type: SNMP Concept
title: "How SNMP Works: Polling, Traps & the Request Flow"
description: "Manager builds a GetRequest, sends it over UDP 161, agent resolves the OID and returns a typed Response."
resource: "https://snmp-monitoring.info/what-is-snmp/how-it-works/"
tags: [what-is-snmp]
timestamp: 2026-07-10T00:00:00Z
---

# How SNMP Works: Polling, Traps & the Request Flow

Manager builds a GetRequest, sends it over UDP 161, agent resolves the OID and returns a typed Response.

## Related concepts

- Up: [What Is SNMP? Simple Network Management Protocol Explained](/what-is-snmp/index.md)

## Frequently asked questions

### How does SNMP poll a device?

Manager fires Get / GetNext / GetBulk at UDP 161. Agent resolves OIDs it implements, returns a Response with types and values (or an error). Your NMS stores the sample and waits for the next interval. Nothing streams by default.

### What port does SNMP use?

Queries: UDP 161 on the agent. Traps/informs: UDP 162 toward the manager/receiver. Both UDP—so write the firewall rules like you mean it, both directions as needed.

### Is SNMP push or pull?

Both. Polling is pull. Traps/informs are push. Capacity graphs lean pull; "link just died" leans push.

### What is an SNMP GetRequest?

It's the "give me these OIDs" PDU. One shot, one or more varbinds. Agent answers with Response. snmpget is basically GetRequest with a pretty printer.

## Source

Concept generated from https://snmp-monitoring.info/what-is-snmp/how-it-works/ — the SNMP Monitoring vendor-neutral knowledge base. Content is limited to what that page states (no external claims added here).