> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vms.verolabs.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Probe: snmp_check

> Poll SNMP OIDs from network devices

<Warning>
  This probe is on the development roadmap.
</Warning>

## Description

The `snmp_check` probe polls OID values from SNMP-enabled devices. Supports SNMPv2c (community string) and SNMPv3 (username + auth/privacy). Credentials are resolved via secret references — never logged.

Build tag `vms_heavy`.

## Config fields

| Field                   | Type       | Required                 | Default          | Description                                                         |
| ----------------------- | ---------- | ------------------------ | ---------------- | ------------------------------------------------------------------- |
| `type`                  | `string`   | Yes                      | —                | Must be `"snmp_check"`                                              |
| `host`                  | `string`   | Yes                      | —                | SNMP target host/IP                                                 |
| `port`                  | `int`      | No                       | `161`            | SNMP port                                                           |
| `version`               | `string`   | Yes                      | —                | `"v2c"` or `"v3"`                                                   |
| `communitySecretRef`    | `string`   | No                       | `"public"` (v2c) | Secret ref for community string                                     |
| `usernameSecretRef`     | `string`   | v3: Yes                  | —                | Secret ref for SNMPv3 username                                      |
| `authProtocol`          | `string`   | No                       | —                | Auth protocol: `md5`, `sha`, `sha224`, `sha256`, `sha384`, `sha512` |
| `authPasswordSecretRef` | `string`   | When authProtocol set    | —                | Secret ref for auth passphrase                                      |
| `privacyProtocol`       | `string`   | No                       | —                | Privacy protocol: `des`, `aes`, `aes192`, `aes256`                  |
| `privPasswordSecretRef` | `string`   | When privacyProtocol set | —                | Secret ref for privacy passphrase                                   |
| `oids`                  | `string[]` | Yes                      | —                | OIDs to GET. At least one required                                  |

## Metrics

| Metric            | Type   | Labels | Description                                 |
| ----------------- | ------ | ------ | ------------------------------------------- |
| `vms.snmp.status` | status | —      | `up` or `down`                              |
| `vms.snmp.value`  | gauge  | `oid`  | Numeric OID value. Non-numeric OIDs skipped |

## Example config

```json theme={null}
{
  "type": "snmp_check",
  "host": "10.0.0.20",
  "port": 161,
  "version": "v2c",
  "communitySecretRef": "SNMP_COMMUNITY_CORE",
  "oids": ["1.3.6.1.2.1.1.3.0"]
}
```

## Notes

* Secret refs resolve via environment variables at construction. Unset ref → probe is skipped.
* Only **numeric** values are emitted as metrics. Non-numeric OID values are skipped.
* Build tag `vms_heavy` — not in default agent package.