DNS Query Script

This script performs DNS queries for a specified domain and record type against a list of DNS servers provided in a YAML file. It uses the dig command to query each DNS server in the list, and returns the results of the query.

Usage

./dns_query.sh <domain> [record_type] <dns_yaml_file>

• domain - The domain name to query.
• record_type - Optional. The type of DNS record to query for. Must be one of A, AAAA, CNAME, MX, NS, PTR, SOA, SRV, or TXT. If not specified, the script will default to querying for A records.
• dns_yaml_file - Required. The YAML file containing the list of DNS servers to query.

Removing DNS servers

The script allows you to remove stale DNS servers from the list. To enable this feature, set the remove_dns_server variable to y in the script before running it.

remove_dns_server="n"

If a DNS server in the list cannot be reached or returns an error for the specified domain and record type, the script will automatically remove it from the list if remove_dns_server is set to y.

YAML file format

The list of DNS servers to query should be provided in a YAML file with the following format:

- reverse: <reverse DNS>
  ip: <IP address>
  provider: <provider name>
  country: <country code>

• reverse - The reverse DNS name for the DNS server.
• ip - The IP address of the DNS server.
• provider - The name of the DNS server provider.
• country - The two-letter country code of the location of the DNS server.

The script comes with two sample YAML files:

• dns_servers_all.yaml - Contains a list of DNS servers from various providers and countries.
• dns_servers_common.yaml - Contains a list of commonly used DNS servers.

You can use one of these files as a starting point for your own list of DNS servers.

Dependencies

This script requires the dig command and the yq tool. If yq is not installed, the script will prompt the user to install it.

License

This project is licensed under the MIT License. See the LICENSE file for more information.

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