Local Network Access Test

Private Network Access (PNA) is a browser security feature that gates requests from public websites to private/local IP addresses.

• The browser sends a CORS preflight (OPTIONS) with the header Access-Control-Request-Private-Network: true.
• The local device must respond with Access-Control-Allow-Private-Network: true (plus standard CORS headers) for the real request to proceed.
• Chrome 104+ enforces this; other browsers are adopting it.
• The targetAddressSpace fetch option ("private" or "local") explicitly opts in to PNA in supporting browsers.

If the device at 192.168.100.1 does not return the required CORS + PNA headers, the request will be blocked by the browser.