I don't see that anyone has recommended this, and it may not be feasible but....you could plug a machine directly in to you ISP's endpoint and do a speed test from there. And then plug directly in to your OPNSense fw and check from there.
You might not have full bandwidth on the public side of your fw. It may not even be an OPNSense issue.
You might not have full bandwidth on the public side of your fw. It may not even be an OPNSense issue.
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