ForwardProxy

Any F5 BIG-IP connected to the internet will be generating this log message a ton in /var/log/ltm:

01260013:4: SSL Handshake failed for TCP x.x.x.x:x -> y.y.y.y:443

This is simply an informational message indicating the peer closed the connection before completing the handshake. As this provides little to no information, you can often safely filter this from the LTM log by creating a log filter.