DNSInfo

dnsinfo is a TypeScript package for forward DNS and reverse DNS discovery across one or more DNS resolvers.

It supports:

• Multiple resolvers in one request
• Per-resolver ports
• IPv4 and IPv6 resolver endpoints
• IPv4 and IPv6 lookup targets
• Results grouped by resolver, then target, then record type

Install

npm install @opsimathically/dnsinfo

Quick Usage

Forward DNS Lookup (Multiple Resolvers)

import { GetDnsRecords } from '@opsimathically/dnsinfo';

async function ExampleForwardLookup(): Promise<void> {
  const dns_results = await GetDnsRecords({
    resolvers: [
      {
        resolver_id: 'google_ipv4',
        resolver_host: '8.8.8.8',
        resolver_port: 53
      },
      '[2001:4860:4860::8888]:53'
    ],
    targets: ['example.com', '1.1.1.1', '2606:4700:4700::1111'],
    record_types: ['A', 'AAAA', 'MX', 'TXT', 'PTR'],
    timeout_ms: 3000,
    max_retries: 1,
    concurrency_limit: 25
  });

  console.log(JSON.stringify(dns_results, null, 2));
}

void ExampleForwardLookup();

Reverse DNS Lookup (PTR)

import { GetReverseDnsRecords } from '@opsimathically/dnsinfo';

async function ExampleReverseLookup(): Promise<void> {
  const reverse_dns_results = await GetReverseDnsRecords({
    resolvers: ['1.1.1.1:53', '8.8.8.8:53'],
    targets: ['8.8.8.8', '2001:4860:4860::8888'],
    timeout_ms: 3000,
    max_retries: 1,
    concurrency_limit: 25
  });

  console.log(JSON.stringify(reverse_dns_results, null, 2));
}

void ExampleReverseLookup();

Public API

• GetDnsRecords(params)
• GetDnsRecordsFromResolvers(params)
• GetReverseDnsRecords(params)

Input types:

• dns_lookup_request_t
• reverse_dns_lookup_request_t

Output types:

• dns_lookup_response_t
• reverse_dns_lookup_response_t

Resolver Input Formats

Resolvers can be supplied in either format:

// Object form
{ resolver_id: 'quad9', resolver_host: '9.9.9.9', resolver_port: 53 }

// String form (IPv4/hostname)
'8.8.8.8:53'
'dns.example.net:53'

// String form (IPv6)
'[2001:4860:4860::8888]:53'

Response Shape

Each response includes request timestamps and resolver_results. Each resolver includes target_results. Each target includes record_results with:

• record_type
• status (success, empty, error)
• answers
• latency_ms
• queried_at
• error_code and error_message when status is error

Runtime Validation

The package validates incoming request payloads at runtime using zod schemas generated by ts-to-zod.

To regenerate schemas:

npm run ts-to-zod

Build and Test

npm run test
npm run build

Additional Examples

• test/dns_lookup/index.test.ts