---
type: SNMP Concept
title: "What Is an OID in SNMP? Object Identifiers Explained"
description: "Object Identifiers explained: dotted notation, sysUpTime decode, scalars vs tables, enterprise branch."
resource: "https://snmp-monitoring.info/what-is-snmp/oid/"
tags: [what-is-snmp]
timestamp: 2026-07-10T00:00:00Z
---

# What Is an OID in SNMP? Object Identifiers Explained

Object Identifiers explained: dotted notation, sysUpTime decode, scalars vs tables, enterprise branch.

## Related concepts

- Up: [What Is SNMP? Simple Network Management Protocol Explained](/what-is-snmp/index.md)
- [Enterprise OIDs (1.3.6.1.4.1): Vendor Numbers Explained](/what-is-snmp/oid/enterprise/index.md)
- [The SNMP OID Tree: Numbering Hierarchy Explained](/what-is-snmp/oid/tree/index.md)

## Frequently asked questions

### What does OID stand for?

Object Identifier—the hierarchical address of a managed object in SNMP (and ASN.1-related naming).

### How do I read an SNMP OID?

Left to right as a path of nodes. Example: 1.3.6.1.2.1.1.3.0 → iso.org.dod.internet.mgmt.mib-2.system.sysUpTime instance 0.

### What does .0 mean?

On scalars, .0 is the instance identifier for the single value. Table cells use row indexes instead.

### Where do vendor OIDs start?

Under the enterprise branch 1.3.6.1.4.1, then a vendor PEN, then their subtree. See enterprise OIDs.

## Source

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