dmg-01

Description

Setup SNMP Prometheus exporter to scrape metrics from Juniper Hardware, specifically tested for the SRX switches. Having looked online i dont see any examples of anyone doing this and so have created a dashboard and process to get this setup.

My homelab setup is an SRX220H2 running Junos 12.3.

Setup SNMP exporter

First thing you need to do is create a snmp.yml file, you do not create this directly instead you create a generator.yml which uses the MIBs to create a working snmp.yml.

Create your /etc/prometheus/generator.yml

generator.yml

modules:
  srx220h2:
    version: 2
    auth:
      community: "homelab"     # or your SNMPv2c community
    walk:
      - sysUpTime
      - jnxRedAlarmState
      - jnxYellowAlarmState
      - ifTable
      - ifXTable
      - jnxOperatingTable               # chassis temps, CPU, memory
      - jnxJsSPUMonitoringObjectsTable  # SRX session & SPU stats
    lookups:
      - source_indexes: [ifIndex]
        lookup: ifDescr
      - source_indexes: [ifIndex]
        lookup: ifAlias

Get the MIBS for junos 12.3 extract and copy to /usr/share/snmp/mibs/

wget https://www.juniper.net/documentation/software/junos/junos123X48/juniper-mibs-12.3X48-D10.3.zip
unzip juniper-mibs-12.3X48-D10.3.zip
cp * /usr/share/snmp/mibs/

Configure snmp and generate the snmp.yml

/etc/snmp/snmp.conf

mibs +ALL
mibdirs /usr/share/snmp/mibs

cd /etc/prometheus
/usr/bin/prometheus-snmp-generator generate

You should now have a working snmp.yml

start the exporter and ensure listening on tcp 9116

systemctl start prometheus-snmp-exporter

If this failed check versions and compatibility.

Setup Prometheus

In prometheus.yml configure a new job for Junos hardware

  - job_name: 'junos_switches'
    scrape_interval: 60s
    scrape_timeout: 30s  # slightly longer than SNMP exporter timeout
    metrics_path: /snmp
    params:
      module:
        - srx220h2
    file_sd_configs:
      - files:
          - 'file_sd/junos_targets.yml'
    relabel_configs:
      - source_labels: [__address__]
        target_label: __param_target
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: 127.0.0.1:9116

With a job configured for junos switches add an instance (list of target IPs) to monitor:

file_sd/junos_targets.yml

- targets:
    - '192.168.1.1'
  labels:
    site: 'DC1'
    model: 'SRX220H2'
    vendor: 'juniper'

Reload Prometheus to start scraping the instance through the SNMP exporter.

systemctl reload prometheus

You should now see the targets in prometheus under /targets on the web interface.

Import the dashboard to your Grafana instance to view metrics.

Macros exist for interface types and names. There is also a macro to specify the instance.

https://grafana.com/grafana/dashboards/23625-junos-12-3-snmp-prometheus/