dns.resolveSrv returns ECONNREFUSED on Windows since v24.13.0 (still broken in v25.x and v26.x)

Version

v24.14.0, v25.8.1

Platform

Microsoft Windows NT 10.0.26200.0 x64

Subsystem

dns (c-ares)

What steps will reproduce the bug?

Run the following script:

const dns = require("dns");

dns.resolveSrv("_mongodb._tcp.mongodb.<your-cluster>.mongodb.net", (err, addresses) => {
  console.log(err ? `error ${err.code}: ${err.message}` : addresses);
});

Run with Node.js >= v24.13.0 on Windows.

How often does it reproduce? Is there a required condition?

100% reproducible on Windows.

No special conditions required.

What is the expected behavior? Why is that the expected behavior?

The SRV query should resolve successfully and return records.

Example output (Node v24.12.0 and v25.2.1):

[
  {
    name: 'shard-00-00.<your-cluster>.mongodb.net',
    port: 27017,
    priority: 0,
    weight: 0,
    type: 'SRV'
  },
  {
    name: 'shard-00-01.<your-cluster>.mongodb.net',
    port: 27017,
    priority: 0,
    weight: 0,
    type: 'SRV'
  },
  {
    name: 'shard-00-02.<your-cluster>.mongodb.net',
    port: 27017,
    priority: 0,
    weight: 0,
    type: 'SRV'
  }
]

This behavior is consistent with:

• previous Node.js versions
• Node.js v25.2.1
• other platforms (tested on Linux)

What do you see instead?

error ECONNREFUSED: querySrv ECONNREFUSED _mongodb._tcp.<your-cluster>.mongodb.net

This happens consistently even with valid public DNS resolvers configured on the system.

Additional information

This appears related to the issue described in #61435 and the fix in #61453 (commit 17b363a66c).

However, the problem persists on Windows.

From testing:

• Node.js 24:

  • Last known working version: v24.12.0
  • First broken version: v24.13.0+

• Node.js 25:

  • Last known working version: v25.2.1
  • Reproducible in all tested versions up to v25.8.1

The issue is 100% reproducible and specifically affects SRV resolution (dns.resolveSrv).

The issue does not occur in earlier versions and is therefore a regression.

This suggests the fix may be incomplete or that the regression was reintroduced.

Beginne mit der dns.resolveSrv-Reproduktion im Issue und vergleiche die Änderungen aus Commit 17b363a66c und Issue #61435, einschließlich des in #61453 nachverfolgten Fixes. Reproduziere das ECONNREFUSED-Ergebnis unter Windows mit den aufgeführten Node.js-Versionen und verifiziere, dass SRV-Abfragen wieder Records zurückgeben, ohne andere Plattformen zu beeinträchtigen.