OPNsense 26.7.2_2: TLS error when connecting to i.ytimg.com

[S1ardust]

Hello,

I am new to OPNsense and  I'm experiencing a strange HTTPS/TLS issue. (Version: 26.7.2_2)
On my Windows 11 Client behind OPNsense, I was missing thumbnails on the YouTube website.

When I try to open the URL "https://i.ytimg.com/vi/FLH1aARTpMg/hq720.jpg" i get the error "ERR_SSL_PROTOCOL_ERROR" in Edge-Browser:

You cannot view this attachment.

After a lot of troubleshooting, with some help from ChatGPT, I was able to reproduce the issue directly from the OPNsense shell.

Most HTTPS traffic works normally. For example:

Code Select Expand

curl -4 -sS -o /dev/null -w '%{http_code}\n' \
https://www.google.com

returns:
200


However, connecting to the YouTube image server directly from OPNsense fails:

Code Select Expand

curl -4 -sS -o /dev/null -w '%{http_code}\n' \
https://i.ytimg.com/vi/FLH1aARTpMg/hq720.jpg

results in:

curl: (35) TLS connect error:
error:0A00010B:SSL routines::wrong version number
000


DNS resolution works correctly, and the same i.ytimg.com IP is reachable. The URL also works normally when the client connects directly through the router instead of OPNsense.

Has anyone seen a similar TLS issue with OPNsense 26.7.x / FreeBSD 15.x?

Any hints on where to investigate further would be greatly appreciated.

EDIT: No Plug-Ins, No relevant Firewall rules, fresh Install

Thank you very much for your support!

[meyergru]

No problem here, neither with opening the site in Edge nor with the given command - it returns 200.

So that is not an OpnSense problem. I would rather suspect a geoip issue, because Youtube has distributed servers. You may have hit a defective one.

[S1ardust]

Hello,

No problem here, neither with opening the site in Edge nor with the given command - it returns 200.

Thank you for checking! 🙏🏻

I found an issue on my network/gateway/router.
It was not an OPNsense problem.

Thank you