check ssl server certificate on client side

I apologize, but the request isn't entirely clear to me. Firstly, I assume that you are not using SSL offload on the BIG-IP. Is that correct? Are you attempting to ensure that the traffic on a specific port uses a TLS handshake before starting? Are you attempting to ensure that the TLS handshake includes a server certificate? While TLS provides mechanisms for operation without certificates (e.g., anonymous key exchange), I don't believe that almost any user-agent supports TLS without at least a server certificate.