captive portal detection fails with redirect from detectportal.firefox.com to mymodem.modem, which does not resolve
My Firefox Developer Edition just required manual help to upgrade to 73.0b2 because the auto-upgrade failed. Not sure if that is important. All new tabs and windows had … (read more)
My Firefox Developer Edition just required manual help to upgrade to 73.0b2 because the auto-upgrade failed. Not sure if that is important. All new tabs and windows had the "You have to connect to the internet" captive-portal bar across the top, but I'm on a home network without captive portal. Clicking the "go to login page" button went to a "can't find that page" error page.
I tried curl from the command-line of my Mac (10.15.2) and got this:
- Trying 2600:1415:1c00::17c0:6c92...
- TCP_NODELAY set
- Connected to detectportal.firefox.com (2600:1415:1c00::17c0:6c92) port 80 (#0)
> GET /success.txt HTTP/1.1 > Host: detectportal.firefox.com > User-Agent: curl/7.64.1 > Accept: */* > < HTTP/1.1 302 Moved Temporarily < Server: nginx < Date: Wed, 08 Jan 2020 10:07:46 GMT < Content-Type: text/html < Content-Length: 154 < Connection: keep-alive < Location: http://mymodem.modem < X-Frame-Options: SAMEORIGIN < Content-Security-Policy: default-src 'self';script-src 'self' 'unsafe-eval' 'unsafe-inline';style-src 'self' 'unsafe-inline' < Cache-Control: public, max-age=31536000 < <title>302 Found</title>
- Connection #0 to host detectportal.firefox.com left intact
- Closing connection 0
I'm prepared to believe that this is ISP-related, rather than Firefox, but on the off-chance that it's somehow down to a misconfiguration of the captive-portal detection servers right now, I thought that I'd report it here.
I've stopped this from happening by setting about:config network.captive-portal-service.enabled to false, but would ideally prefer that this not recur on the next profile reset.