fetch() ETIMEDOUT on specific Cloudflare IPs while curl.exe works on Windows

Why this is a good first issue

Platform-specific networking issue with unclear root cause despite reproduction attempts.

AI Summary

The issue involves Node.js fetch() timing out on specific Cloudflare IPs on Windows while other tools work, suggesting a platform-specific networking stack problem. The root cause isn't immediately clear despite reproduction attempts, and it may involve undici's connection handling. The maintainer has pointed to a potential related undici issue, indicating this might require deeper networking knowledge to diagnose.

Issue Description

Version

Node.js v22.22.0 Windows 11 (Build 26100)

Platform

Windows_NT 10.0.26100 x64

Subsystem

net, undici (fetch)

What steps will reproduce the bug?

Run this command on Windows:

node -e "fetch('https://shadcn-vue.com').then(r => console.log(r.status)).catch(e => console.log(e.message))"

Result: fetch failed with ETIMEDOUT
Run with curl.exe on the same machine:

curl.exe -I https://shadcn-vue.com

Result: HTTP/1.1 200 OK

Additional context

Same network, same site, different results:
- curl.exe → Works (200)
- PowerShell Invoke-WebRequest → Works (200)
- Node.js fetch() → ETIMEDOUT
- Node.js require('https').get() → Hangs forever
Other sites work fine in Node.js:
- https://google.com → 200 ✓
- https://github.com → 200 ✓
- https://cloudflare.com → 200 ✓
- https://shadcn-vue.com → ETIMEDOUT ✗
Same code works on Mac:
- Tested on macOS with the same Node.js version on the same network → Returns 200

Error details

AggregateError [ETIMEDOUT]:
    at internalConnectMultiple (node:net:1134:18)
    at afterConnectMultiple (node:net:1715:7) {
  code: 'ETIMEDOUT',
  [errors]: [
    Error: connect ETIMEDOUT 172.67.178.160:443 {
      errno: -4039,
      code: 'ETIMEDOUT',
      syscall: 'connect',
      address: '172.67.178.160',
      port: 443
    },
    Error: connect ENETUNREACH 2606:4700:3033::6815:11e2:443 {
      errno: -4062,
      code: 'ENETUNREACH',
      syscall: 'connect',
      address: '2606:4700:3033::6815:11e2',
      port: 443
    },
    Error: connect ETIMEDOUT 104.21.17.226:443 {
      errno: -4039,
      code: 'ETIMEDOUT',
      syscall: 'connect',
      address: '104.21.17.226',
      port: 443
    },
    Error: connect ENETUNREACH 2606:4700:3037::ac43:b2a0:443 {
      errno: -4062,
      code: 'ENETUNREACH',
      syscall: 'connect',
      address: '2606:4700:3037::ac43:b2a0',
      port: 443
    }
  ]
}