codex - 💡(How to fix) Fix Windows Desktop: sandboxed shell can resolve and ping LAN host but HTTP/TCP connection fails [1 participants]

What version of the Codex App are you using?

Unknown / can provide if needed.

What platform is your computer?

Windows desktop app.

What issue are you seeing?

Codex Desktop's shell/tool environment can resolve and ping an internal LAN host, but cannot establish HTTP/TCP connections to it. The same URL works from the browser and from normal PowerShell on the same Windows machine.

This appears specific to Codex's sandbox/helper process rather than DNS or the internal service itself.

Observed behavior

From normal Windows PowerShell outside Codex:

Invoke-WebRequest http://internal-app.local

returns:

StatusCode        : 200
StatusDescription : OK

From inside Codex Desktop's shell tool:

Resolve-DnsName internal-app.local

succeeds and returns a LAN address.

Test-Connection internal-app.local -Count 1

also succeeds.

But:

Invoke-WebRequest http://internal-app.local

fails with:

Unable to connect to the remote server

Direct HTTP to the resolved LAN IP and app port also fails from Codex with the same connection failure.

Expected behavior

If the shell/tool environment is permitted to use network access, Codex should be able to make the same LAN HTTP/TCP request that browser and normal PowerShell can make from the same Windows machine.

Why this looks like a Codex sandbox/network issue

• Browser on the same machine can reach the internal app.
• Normal PowerShell on the same machine can reach the internal app.
• Codex can resolve the hostname.
• Codex can ping the host.
• Codex cannot open HTTP/TCP to that host.
• This reportedly worked from Codex Desktop last week with the same internal service configuration.

Notes

Hostnames and IPs are intentionally sanitized because this is an internal production LAN service.