SNMP OID

This document is a reference material that systematically organizes OID (Object Identifier) information required when configuring SNMP GET collectors.

Understanding OID Structure

OID Tree Structure

SNMP OIDs have a hierarchical tree structure where each node inherits a unique number from its parent node. This is similar to a file system directory structure.

Hierarchical Structure from Root Node

1              - ISO (International Organization for Standardization)
└── 1.3        - org (ISO identified organization)
    └── 1.3.6  - dod (US Department of Defense)
        └── 1.3.6.1 - internet (Internet)
            ├── 1.3.6.1.1   - directory (X.500 Directory)
            ├── 1.3.6.1.2   - mgmt (Management)
            │   └── 1.3.6.1.2.1 - mib-2 (MIB-II, standard management objects)
            ├── 1.3.6.1.3   - experimental (experimental objects)
            ├── 1.3.6.1.4   - private (private)
            │   └── 1.3.6.1.4.1 - enterprises (enterprise-specific private objects)
            ├── 1.3.6.1.5   - security (security)
            ├── 1.3.6.1.6   - snmpV2 (SNMPv2)
            ├── 1.3.6.1.7   - mail (mail)
            └── 1.3.6.1.8   - features (features)

Role and Management Authority of Each Branch

Benefits of Hierarchical Structure

1. Uniqueness Guarantee: Each OID is a globally unique identifier
2. Scalability: New nodes can be added to existing structure
3. Management Efficiency: Clear separation of management authority per branch
4. Standardization: Systematic standard management through RFC documents

Real OID Example Interpretation

Example: 1.3.6.1.2.1.1.1.0 (system description)

1       - ISO root
1.3     - ISO identified organization
1.3.6   - US Department of Defense
1.3.6.1 - Internet
1.3.6.1.2 - Management objects
1.3.6.1.2.1 - MIB-II standard
1.3.6.1.2.1.1 - system group
1.3.6.1.2.1.1.1 - sysDescr object
1.3.6.1.2.1.1.1.0 - scalar instance (single value)

Example: 1.3.6.1.4.1.9.2.1.56.0 (Cisco CPU utilization)

1.3.6.1.4.1 - Enterprise private branch
1.3.6.1.4.1.9 - Cisco Systems (enterprise number: 9)
1.3.6.1.4.1.9.2.1.56.0 - avgBusy5 (5-minute average CPU utilization)

Notation Methods

Numeric Notation (used in Sonar collectors):

1.3.6.1.2.1.1.1.0

Name Notation (used in MIB files):

iso.org.dod.internet.mgmt.mib-2.system.sysDescr.0

Major Standard OIDs

System Group (1.3.6.1.2.1.1)

OIDs that provide basic system information.

Interfaces Group (1.3.6.1.2.1.2)

OIDs that provide network interface information.

Basic Interface Information

Traffic Statistics (32-bit Counters)

Note: X is the interface index number. Example: 1.3.6.1.2.1.2.2.1.10.1 (received bytes of first interface)

High Capacity Counters (1.3.6.1.2.1.31)

64-bit counters for high-speed interfaces.

Host Resources MIB (1.3.6.1.2.1.25)

OIDs that provide system resource information.

System Information

Memory Information

CPU Information

Vendor-Specific Private Enterprise OIDs

Cisco Systems (1.3.6.1.4.1.9)

Major Cisco OIDs:

1.3.6.1.4.1.9.2.1.56.0    - avgBusy5 (5-minute average CPU utilization)
1.3.6.1.4.1.9.2.1.57.0    - avgBusy1 (1-minute average CPU utilization)
1.3.6.1.4.1.9.9.48.1.1.1.5.X - cpmCPUTotal5min (CPU 5-minute average)

HP Enterprise (1.3.6.1.4.1.11)

Major HP OIDs:

1.3.6.1.4.1.11.2.14.11.5.1.9.6.1.0 - hpSwitchCpuStat (CPU statistics)

Net-SNMP (1.3.6.1.4.1.8072)

Major Net-SNMP OIDs:

1.3.6.1.4.1.8072.1.3.2.3.1.2.X - ssSwapIn (swap usage)
1.3.6.1.4.1.8072.1.3.2.4.1.2.X - ssCpuUser (user CPU)

Practical Usage Guide

1. OID Discovery Methods

Linux/macOS

Installing Net-SNMP Tools:

Ubuntu/Debian systems:

sudo apt-get install snmp snmp-mibs-downloader

CentOS/RHEL systems:

sudo yum install net-snmp-utils

macOS (Homebrew):

brew install net-snmp

Basic discovery commands:

Query all system information:

snmpwalk -v2c -c public 192.168.1.1 1.3.6.1.2.1.1

Query interface information:

snmpwalk -v2c -c public 192.168.1.1 1.3.6.1.2.1.2.2.1.2

Query specific OID value:

snmpget -v2c -c public 192.168.1.1 1.3.6.1.2.1.1.1.0

Display in table format:

snmptable -v2c -c public 192.168.1.1 1.3.6.1.2.1.2.2

Windows

Method 1: Net-SNMP for Windows

1. Download and Installation:

   • Download from Net-SNMP Windows Binaries
   • Use in Command Prompt (CMD) or PowerShell after installation

2. Command Usage (same as Linux):

   Query all system information:

   snmpwalk -v2c -c public 192.168.1.1 1.3.6.1.2.1.1
   

   Query interface information:

   snmpwalk -v2c -c public 192.168.1.1 1.3.6.1.2.1.2.2.1.2
   

   Query specific OID value:

   snmpget -v2c -c public 192.168.1.1 1.3.6.1.2.1.1.1.0
   

Method 2: PowerShell SNMP Module

1. Install SNMP Module:

   Install SNMP module from PowerShell Gallery:

   Install-Module -Name SNMP -Force
   

2. PowerShell Commands:

   Query specific OID value:

   Get-SnmpData -IP "192.168.1.1" -Community "public" -OID "1.3.6.1.2.1.1.1.0"
   

   OID Walk (PowerShell script example) - Query system information:

   $target = "192.168.1.1"
   $community = "public"
   $baseOid = "1.3.6.1.2.1.1"
   
   1..6 | ForEach-Object {
       $oid = "$baseOid.$_.0"
       try {
           $result = Get-SnmpData -IP $target -Community $community -OID $oid -UDPport 161
           Write-Host "$oid : $($result.Data)"
       }
       catch {
           Write-Host "$oid : Error - $($_.Exception.Message)"
       }
   }
   

Method 3: GUI Tools

• ManageEngine MibBrowser: Free MIB browser
• iReasoning MIB Browser: Commercial MIB browser

Recommended Installation Path:

1. Developers/IT Administrators: Net-SNMP for Windows (prefer command-line tools)
2. PowerShell Users: PowerShell SNMP module
3. General Users: GUI tools (MIB Browser, etc.)

2. SNMP GET Collector Configuration Examples

System monitoring:

1.3.6.1.2.1.1.1.0=system_description,1.3.6.1.2.1.1.3.0=uptime,1.3.6.1.2.1.25.1.1.0=hr_uptime

Interface traffic monitoring:

1.3.6.1.2.1.2.2.1.10.1=if1_in_octets,1.3.6.1.2.1.2.2.1.16.1=if1_out_octets,1.3.6.1.2.1.31.1.1.1.6.1=if1_hc_in_octets

CPU and memory monitoring:

1.3.6.1.2.1.25.3.3.1.2.1=cpu_load,1.3.6.1.2.1.25.2.2.0=memory_size,1.3.6.1.2.1.25.2.3.1.6.1=memory_used

3. 32-bit vs 64-bit Counter Selection

4. Counter Wrap Around Time Calculation

32-bit counter maximum value: 4,294,967,295

Wrap Around time examples:

• 10 Mbps: approximately 57 minutes
• 100 Mbps: approximately 5.7 minutes
• 1 Gbps: approximately 34 seconds

Online Reference Materials

Official Standard Documents

• RFC 1155: Structure and Identification of Management Information
• RFC 1213: Management Information Base for Network Management (MIB-II)
• RFC 2578: Structure of Management Information Version 2 (SMIv2)
• RFC 2233: The Interfaces Group MIB using SMIv2

OID Databases

• Object Identifier Repository: Comprehensive OID database and search
• IANA Structure of Management Information: Official SMI numbers and MIB-II registry
• IANA Private Enterprise Numbers: Official enterprise number registry
• MonitorTools MIB Collection: Vendor-specific MIB file collection

Vendor-Specific MIB Information

• Cisco SNMP Object Navigator: Cisco MIB object search
• Juniper MIB Explorer: Juniper device MIB information

This reference material enables effective SNMP GET collector configuration and collection of various information from network devices.