Monitoring SNMP

Configure the Server Density agent to monitor SNMP to:

• Collect metrics from your SNMP devices

Monitored metrics

The SNMP plugin does not automatically collect metrics. You must configure the plugin to collect specific metrics.

Installing the SNMP Plugin

Install the SNMP plugin on Debian/Ubuntu:

sudo apt-get install sd-agent-snmp

Install the SNMP plugin on RHEL/CentOS:

sudo yum install sd-agent-snmp

Read more about agent plugins.

Configuring the agent to monitor via SNMP

1. Configure /etc/sd-agent/conf.d/snmp.yaml

The SNMP check does not automatically collect metrics. You must configure the plugin to collect specific metrics.

init_config:
   - mibs_folder: /path/to/your/mibs

instances:
   - ip_address: localhost
     port: 161
     community_string: public
#    snmp_version: 1 # set to 1 if your devices use SNMP v1; no need to set otherwise, the default is 2
     timeout: 1      # in seconds; default is 1
     retries: 5
#    enforce_mib_constraints: false # set to false to NOT verify that returned values meet MIB constraints; default is true
     metrics:
       - MIB: UDP-MIB
         symbol: udpInDatagrams
       - OID: 1.3.6.1.2.1.6.5
         name: tcpPassiveOpens
       - MIB: IF-MIB
         table: ifTable
         symbols:
           - ifInOctets
           - ifOutOctets
         metric_tags:
           - tag: interface
             column: ifDescr>

You can collect metrics from multiple SNMP enabled devices by listing each device as it's own instance in your snmp.yaml. 

There are 3 different ways that you can specify which metrics to collect in your snmp.yaml; MIB and symbol, OID and name and MIB and table

MIB and Symbol

    metrics:
      - MIB: UDP-MIB
        symbol: udpInDatagrams 

OID and Name

    metrics:
      - OID: 1.3.6.1.2.1.6.5
        name: tcpActiveOpens # what to use in the metric name; can be anything

MIB and Table

    metrics:
      - MIB: IF-MIB
        table: ifTable
        symbols:
          - ifInOctets      # row whose value becomes metric value
        metric_tags:
          - tag: interface  # tag name
            column: ifDescr # the column name to get the tag value from, OR
            #index: 1       # the column index to get the tag value from

Using your own MIB

It's possible to use your own MIBs if they are formatted via pysnmp. You can use the build-pysnmp-mibs script that ships with the agent to generate this data.

 /usr/share/python/sd-agent/bin/build-pysnmp-mib  -o /path/to/your/mibs mib-input-text-file  

2. Restart the agent

sudo /etc/init.d/sd-agent restart

Verifying the configuration
Execute info to verify the configuration with the following:

sudo /etc/init.d/sd-agent info 

If the agent has been configured correctly you’ll see an output such as:

snmp
-----
  - instance #0 [OK]
  - Collected 32 metrics, 0 events & 0 service checks

You can also check the metrics that the check is returning with the following command

sudo -u sd-agent /usr/share/python/sd-agent/agent.py check snmp