---
type: SNMP Concept
title: "SNMP Trap vs Inform: Acknowledged Notifications"
description: "Compare SNMP traps and InformRequest: acknowledgment, retransmission, UDP 162, SNMPv2c."
resource: "https://snmp-monitoring.info/what-is-snmp/traps-vs-polling/informs/"
tags: [what-is-snmp]
timestamp: 2026-07-10T00:00:00Z
---

# SNMP Trap vs Inform: Acknowledged Notifications

Compare SNMP traps and InformRequest: acknowledgment, retransmission, UDP 162, SNMPv2c.

## Related concepts

- Up: [SNMP Traps vs Polling: Differences & When to Use Each](/what-is-snmp/traps-vs-polling/index.md)

## Frequently asked questions

### Difference between a trap and an inform?

A trap is sent once with no ack. An inform (InformRequest) expects a Response and retransmits if the ack is missing.

### Are SNMP informs acknowledged?

Yes. The receiver acknowledges with a Response; that's the point of InformRequest.

### Which is more reliable?

Informs are more reliable than classic traps because of ack + retry. Neither is perfect on a dead path or dead receiver.

### Which version added informs?

SNMPv2c introduced informs. They're not part of the original SNMPv1 trap-only story.

## Source

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