Monitor SNMP devices

Poll network devices, such as switches, routers, and firewalls, for system and per-interface metrics over SNMP, and write them to InfluxDB 3.

Configuration

[[inputs.snmp]]
  ## Devices to poll.
  agents = ["udp://switch1.example.com:161", "udp://switch2.example.com:161"]

  ## SNMP version and community string.
  version = 2
  community = "public"

  ## Use the "source" tag for the device address, consistent with
  ## other plugins.
  agent_host_tag = "source"

  ## Device-level values collected once per poll.
  [[inputs.snmp.field]]
    oid = "RFC1213-MIB::sysUpTime.0"
    name = "uptime"

  [[inputs.snmp.field]]
    oid = "RFC1213-MIB::sysName.0"
    name = "sysName"
    is_tag = true

  ## Per-interface values collected from the interfaces table.
  [[inputs.snmp.table]]
    oid = "IF-MIB::ifTable"
    name = "interface"
    inherit_tags = ["sysName"]

    ## Tag rows by interface name.
    [[inputs.snmp.table.field]]
      oid = "IF-MIB::ifDescr"
      name = "ifDescr"
      is_tag = true

[[outputs.influxdb_v3]]
  urls = ["http://localhost:8181"]
  token = "
AUTH_TOKEN
"
  database = "
DATABASE_NAME
"

Replace the following:

• AUTH_TOKEN: your InfluxDB authorization token
• DATABASE_NAME: the database to write to

How it works

• agents lists the devices to poll. One plugin instance polls every agent with the same credentials and field definitions. Metrics carry a source tag identifying the device.
• [[inputs.snmp.field]] entries read single (scalar) values. sysUpTime becomes an uptime field, and sysName becomes a tag on every metric from the device.
• [[inputs.snmp.table]] walks the IF-MIB::ifTable and produces one metric per table row, so each interface gets its own interface metric with counters such as ifInOctets, ifOutOctets, and ifOperStatus as fields. The ifDescr column is stored as a tag to identify the interface, and inherit_tags copies the device-level sysName tag onto each row.
• For SNMPv3, replace community with the sec_name, sec_level, auth_protocol, and priv_protocol options from the plugin documentation, and keep passwords out of the config file with secret stores.

Example output

snmp,source=switch1.example.com,sysName=sw-core-01 uptime=1284923i 1709572230000000000
interface,ifDescr=GigabitEthernet0/1,source=switch1.example.com,sysName=sw-core-01 ifInOctets=918273645i,ifOutOctets=234981723i,ifOperStatus=1i,ifSpeed=1000000000i 1709572230000000000
interface,ifDescr=GigabitEthernet0/2,source=switch1.example.com,sysName=sw-core-01 ifInOctets=81723645i,ifOutOctets=34981723i,ifOperStatus=2i,ifSpeed=1000000000i 1709572230000000000

Extend this example

• Interface octet counters are cumulative. Compute per-interval rates at query time, or use the derivative aggregator to emit rates directly.
• To collect only specific columns instead of the whole table, list them as [[inputs.snmp.table.field]] entries and remove the table walk of unneeded columns with index_as_tag and column filters described in the plugin documentation.
• Poll many devices efficiently by increasing max_repetitions for bulk requests, and set per-plugin interval to poll SNMP less often than your other inputs.