FxM is not displaying any https/SSL metrics at all.
I can load my SSL Key files into FxM without error. I know that if the SSL Keys load without error, then most likely the keys are valid. But just to be on the safe side, I've verified from the installguide.pdf that the key file is in a file format that FxM supports (PEM), is using a supported key exchange algorithm (RAS), and is using a supported Bulk Encryption Algorithm (3DES).
I'm certain that the reason is not that the SPAN port is misconfigured (only seeing one-way 1/2 the traffic to the server). I am seeing both Client and Server packet counts--both directions.
I'm certain that we don't have the SSL Key files assigned to the wrong servers. And I'm sure that the SSL traffic is actually going across a server for which an SSL Key has been configured. The SSL traffic matches the server.
We are not using any HTTP accelerators or proxies that could somehow be modifying the structure of the HTTP packets.
From looking at the System Health metrics, I see that all of the SSL connections are being dropped by FxM. And there are lots of SSL Connection Errors too.
One odd thing I noticed is there is exactly the same amount of traffic every five minutes.
You may not have any live traffic on your site. All the traffic may be being generated by asynthetic traffic generator. Most of them do non-standard things at the SSL and HTTP level. And a lot of them generate really strange traffic that would never occur on a live site. Or they can change the structure of the HTTP packets by making them longer. So, FxM is not designed to see that traffic and is not seeing that traffic.
Manually browse to your URLs so that they are hit with some live traffic. FxM should not drop that traffic.