About

Tool for lookup lots of DNS records from multiple nameservers.

Can be used for:

• DNS troubleshooting in complex infrastructures with multiple nameservers
• Troubleshooting different queries results from different networks
• DNS records inventory
• DNS records monitoring

Currently supported output formats:

• JSON
• Pretty JSON
• YAML
• CSV

sequenceDiagram
    activate dns-checker.sh
    dns-checker.sh->>1.1.1.1: mail.google.com A?
    activate 1.1.1.1
    1.1.1.1-->>dns-checker.sh: 142.250.185.101
    deactivate 1.1.1.1
    dns-checker.sh->>1.1.1.1: meet.google.com A?
    activate 1.1.1.1
    1.1.1.1-->>dns-checker.sh: 142.250.186.78
    deactivate 1.1.1.1
    dns-checker.sh->>8.8.8.8: mail.google.com A?
    activate 8.8.8.8
    8.8.8.8-->>dns-checker.sh: 173.194.73.83
    deactivate 8.8.8.8
    dns-checker.sh->>8.8.8.8: meet.google.com A?
    activate 8.8.8.8
    8.8.8.8-->>dns-checker.sh: 173.194.221.113
    deactivate 8.8.8.8
    dns-checker.sh->>1.1.1.1: google.com MX?
    activate 1.1.1.1
    1.1.1.1-->>dns-checker.sh: 10 smtp.google.com.
    deactivate 1.1.1.1
    dns-checker.sh->>8.8.8.8: google.com MX?
    activate 8.8.8.8
    8.8.8.8-->>dns-checker.sh: 10 smtp.google.com.
    deactivate 8.8.8.8
    dns-checker.sh-)Json or yaml output: Aggregated DNS lookup results
    deactivate dns-checker.sh

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Requirements

Required utilities:

• jq
• dig
• grep
• date
• sed

Optional utilities:

• yq - if YAML format used

How to use

1. Clone repository.
2. Create config.json or config.yaml configuration files. See the format below.
3. chmod +x dns-checker.sh
4. Execute dns-checker.sh

Configuration format

Configuration file should be named config.json or config.yaml.

Default input is config.json, then try config.yaml.

Parameter	Required	Value	Exaple
.datetime_format	No	Date format in linux date command syntax. Dafault is --iso-8601=seconds	"datetime_format": "-u --iso-8601=seconds"
.output	No	Allowed values: json, pretty_json, yaml, csv, html. Default is json.	"output": "json"
.nameservers[]	Yes	List of nameservers	"nameservers": ["8.8.8.8","1.1.1.1"]
.lookup[]	Yes	List of dicts	"lookup": [{"zone": "google.com","domains": ["mail","meet"]}]
.lookup[].type	No	Type of DNS record. Default is A.	"type": "MX"
.lookup[].zone	No	DNS zone. No default value.	"zone": "google.com"
.lookup[].domains[]	Yes	List of domains to lookup	"lookup": [{"domains": ["mail.google.com","meet.google.com"]}]

YAML example:

---
datetime_format: -u --iso-8601=seconds  # Date format. Optional.
output: json            # Values: json, pretty_json, yaml, csv, html. Default is json. Optional. 
nameservers:            # List of nameservers. Required.
  - 8.8.8.8
  - 1.1.1.1
lookup:                 # List of records. Required.
  - type: A             # Record type. Default is A. Optional.
    zone: com           # Zone. Optional.
    domains:            # List of domains of specified zones. Required.
      - google
      - www.example
  - type: MX            # Record type. Default is A. Optional.
    domains:            # List of domains in FQDN format (no zone specified). Required.
      - google.com
      - example.com

JSON example:

{
  "datetime_format": "-u --iso-8601=seconds",
  "output": "json",
  "nameservers": [
    "8.8.8.8",
    "1.1.1.1"
  ],
  "lookup": [
    {
      "type": "A",
      "zone": "com",
      "domains": [
        "google",
        "www.example"
      ]
    },
    {
      "type": "MX",
      "domains": [
        "google.com",
        "example.com"
      ]
    }
  ]
}

Usage example

Configuration:

{
  "datetime_format": "-u --iso-8601=seconds",
  "output": "pretty_json",
  "nameservers": [
    "8.8.8.8",
    "1.1.1.1"
  ],
  "lookup": [
    {
      "zone": "google.com",
      "domains": [
        "mail",
        "meet"
      ]
    }
  ]
}

Run script:

chmod +x dns-checker.sh && ./dns-checker.sh

Output:

{
  "data": [
    {
      "datetime": "2025-06-11T18:36:55+00:00",
      "nameserver": "8.8.8.8",
      "zone": ".google.com",
      "domain": "mail",
      "fqdn": "mail.google.com",
      "type": "A",
      "lookup": [
        "216.58.211.5"
      ]
    },
    {
      "datetime": "2025-06-11T18:36:55+00:00",
      "nameserver": "8.8.8.8",
      "zone": ".google.com",
      "domain": "meet",
      "fqdn": "meet.google.com",
      "type": "A",
      "lookup": [
        "142.250.74.174"
      ]
    },
    {
      "datetime": "2025-06-11T18:36:55+00:00",
      "nameserver": "1.1.1.1",
      "zone": ".google.com",
      "domain": "mail",
      "fqdn": "mail.google.com",
      "type": "A",
      "lookup": [
        "142.250.185.229"
      ]
    },
    {
      "datetime": "2025-06-11T18:36:55+00:00",
      "nameserver": "1.1.1.1",
      "zone": ".google.com",
      "domain": "meet",
      "fqdn": "meet.google.com",
      "type": "A",
      "lookup": [
        "142.250.185.206"
      ]
    }
  ],
  "errors": []
}