René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"dns.resolveSrv returns ECONNREFUSED on Windows since v24.13.0 (still broken in v25.x and v26.x)","articleBody":"### Version\n\nv24.14.0, v25.8.1\n\n### Platform\n\n```text\nMicrosoft Windows NT 10.0.26200.0 x64\n```\n\n### Subsystem\n\ndns (c-ares)\n\n### What steps will reproduce the bug?\n\nRun the following script:\n\n```js\nconst dns = require(\"dns\");\n\ndns.resolveSrv(\"_mongodb._tcp.mongodb.\u003cyour-cluster\u003e.mongodb.net\", (err, addresses) =\u003e {\n  console.log(err ? `error ${err.code}: ${err.message}` : addresses);\n});\n```\n\nRun with Node.js \u003e= v24.13.0 on Windows.\n\n### How often does it reproduce? Is there a required condition?\n\n100% reproducible on Windows.\n\nNo special conditions required.\n\n### What is the expected behavior? Why is that the expected behavior?\n\nThe SRV query should resolve successfully and return records.\n\nExample output (Node v24.12.0 and v25.2.1):\n\n```\n[\n  {\n    name: 'shard-00-00.\u003cyour-cluster\u003e.mongodb.net',\n    port: 27017,\n    priority: 0,\n    weight: 0,\n    type: 'SRV'\n  },\n  {\n    name: 'shard-00-01.\u003cyour-cluster\u003e.mongodb.net',\n    port: 27017,\n    priority: 0,\n    weight: 0,\n    type: 'SRV'\n  },\n  {\n    name: 'shard-00-02.\u003cyour-cluster\u003e.mongodb.net',\n    port: 27017,\n    priority: 0,\n    weight: 0,\n    type: 'SRV'\n  }\n]\n```\n\nThis behavior is consistent with:\n- previous Node.js versions\n- Node.js v25.2.1\n- other platforms (tested on Linux)\n\n### What do you see instead?\n\n```\nerror ECONNREFUSED: querySrv ECONNREFUSED _mongodb._tcp.\u003cyour-cluster\u003e.mongodb.net\n```\n\nThis happens consistently even with valid public DNS resolvers configured on the system.\n\n### Additional information\n\nThis appears related to the issue described in #61435 and the fix in #61453 (commit 17b363a66c).\n\nHowever, the problem persists on Windows.\n\nFrom testing:\n\n- Node.js 24:\n  - Last known working version: v24.12.0\n  - First broken version: v24.13.0+\n\n- Node.js 25:\n  - Last known working version: v25.2.1\n  - Reproducible in all tested versions up to v25.8.1\n\nThe issue is 100% reproducible and specifically affects SRV resolution (`dns.resolveSrv`).\n\nThe issue does not occur in earlier versions and is therefore a regression.\n\nThis suggests the fix may be incomplete or that the regression was reintroduced.","author":{"url":"https://github.com/niridya","@type":"Person","name":"niridya"},"datePublished":"2026-03-18T19:33:04.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":10},"url":"https://github.com/62326/node/issues/62326"}