---
type: Sensor Reference
title: "SNMP Uptime OID: sysUpTime vs hrSystemUptime Reference"
description: "The SNMP uptime OIDs — sysUpTime (agent) vs hrSystemUptime (host boot) — with TimeTicks decoding and a snmpget example."
resource: "https://snmp-monitoring.info/sensors/uptime/"
tags: [sensors]
timestamp: 2026-07-11T00:00:00Z
---

# SNMP Uptime OID: sysUpTime vs hrSystemUptime Reference

The SNMP uptime OIDs — sysUpTime (agent) vs hrSystemUptime (host boot) — with TimeTicks decoding and a snmpget example.

## Related concepts

- Up: [SNMP Sensors & OID Catalog: Every Metric You Can Monitor](/sensors/index.md)

## Frequently asked questions

### What is the OID for uptime in SNMP?

Two of them: sysUpTime at 1.3.6.1.2.1.1.3.0 (time since the SNMP agent restarted) and hrSystemUptime at 1.3.6.1.2.1.25.1.1.0 (time since the host booted). Both return TimeTicks in hundredths of a second. Use hrSystemUptime when you mean actual machine uptime.

### What's the difference between sysUpTime and hrSystemUptime?

sysUpTime tracks the SNMP agent's runtime, so it resets when snmpd restarts — which can happen without a reboot. hrSystemUptime tracks the host's runtime since boot, so it only resets on an actual reboot. Restart the agent for a config change and the two diverge.

### What are TimeTicks?

A TimeTicks value counts hundredths of a second (centiseconds) since some event. It's a 32-bit unsigned counter, so it wraps after roughly 497 days. To get seconds, divide by 100; for days, divide by 8,640,000.

### How do I convert TimeTicks to days?

Divide the raw TimeTicks value by 8,640,000 (that's 100 ticks/second × 86,400 seconds/day). For example, 884213700 ÷ 8,640,000 ≈ 102.3 days. For seconds, divide by 100 instead.

## Source

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