Basic SNMP Configuration

Basic SNMP Configuration

RouterOS Version

Primary Version: 7.16 | Minimum: 6.0 | Difficulty: Beginner | Time: 5 minutes

TL;DR (Quick Start)

For the impatient: here’s the 30-second version.

# Enable SNMP with read-only community
/snmp set enabled=yes
/snmp community add name=public addresses=192.168.88.0/24 read-access=yes write-access=no

Overview

This guide demonstrates how to configure SNMP on MikroTik RouterOS for network monitoring.

Prerequisites

• A MikroTik router running RouterOS 7.x or later
• Access to the router via SSH, WinBox, or WebFig

Configuration Steps

Step 1: Enable SNMP

Enable the SNMP service with basic settings:

/snmp set enabled=yes contact="[email protected]" location="Server Room A"

Step 2: Create an SNMP Community

Create a read-only SNMP community:

/snmp community add name=monitoring addresses=192.168.88.0/24 read-access=yes write-access=no comment="Monitoring system"

Step 3: Create a Write Community

Create a community with write access for management:

/snmp community add name=management addresses=192.168.88.10/32 read-access=yes write-access=yes comment="SNMP management"

Verification

Check 1: SNMP Service Status

/snmp print

Expected Output:

          enabled: yes
          contact: [email protected]
         location: Server Room A
       engine-id:
       trap-target:
   trap-community: public
     trap-version: 1
  trap-generators:

Check 2: SNMP Communities

/snmp community print

Expected Output:

Flags: * - default, X - disabled
 #   NAME        ADDRESSES          SECURITY   READ-ACCESS  WRITE-ACCESS
 0 * public                         none       yes          no
 1   monitoring  192.168.88.0/24    none       yes          no
 2   management  192.168.88.10/32   none       yes          yes

Check 3: Test SNMP (from monitoring system)

# From Linux/monitoring server
snmpwalk -v2c -c monitoring 192.168.88.1 system

Troubleshooting

Problem: SNMP queries not working

Symptoms: Monitoring system cannot poll router, snmpwalk times out.

Causes & Solutions:

1. Source IP not allowed - Check community addresses:

   /snmp community print

   Add monitoring server IP to allowed addresses.

2. Wrong community string - Verify community name matches exactly (case-sensitive).

3. SNMP service disabled - Enable SNMP:

   /snmp set enabled=yes

4. Firewall blocking SNMP - Allow UDP 161 from monitoring network:

   /ip firewall filter add chain=input action=accept protocol=udp dst-port=161 src-address=192.168.88.0/24

Problem: SNMP traps not received

Symptoms: Monitoring system doesn’t receive SNMP traps.

Causes & Solutions:

1. Trap target not configured:

   /snmp set trap-target=192.168.88.50

2. Trap generators not enabled:

   /snmp set trap-generators=interfaces,start-trap

3. Firewall blocking outbound traps - Allow UDP 162 outbound.

Problem: Write access not working

Symptoms: Cannot modify router via SNMP SET commands.

Causes & Solutions:

1. Community has no write access:

   /snmp community print

   Ensure write-access=yes for the community.

2. Using SNMPv1 - Some write operations require SNMPv2c or v3.

Problem: High CPU during SNMP polling

Symptoms: Router CPU spikes during SNMP queries.

Causes & Solutions:

1. Polling too frequently - Reduce polling interval on monitoring system.

2. Polling too many OIDs - Query only needed OIDs rather than walking entire MIB.

3. Many concurrent queries - Stagger polling from multiple monitoring systems

Related Topics

Security

• Firewall Basics - restrict SNMP access by IP
• User Management - SNMPv3 authentication

Monitoring Integration

• Logging - SNMP traps complement logging
• Graphing - built-in graphing alternative
• Torch - real-time traffic monitoring

Advanced Usage

• Scheduler - scheduled SNMP queries via scripts

References

• MikroTik SNMP Documentation