(no major updates with WS 2019)The Hyper-V Extensible Switch in server 2012 provides port mirroring, which allows an administrator to designate which virtual ports should be monitored and to which virtual port the monitored traffic should be delivered for further processing. For example, a security monitoring virtual machine can look for anomalous patterns in the traffic flowing through other specific virtual machines on the switch. In addition, an administrator can diagnose network connectivity issues by monitoring traffic bound for a particular virtual switch port.

New with WS 2012 R2 is a streamlined and more detailed network tracing capability - network traces now contain switch and port configuration information, and tracing packets through the Hyper-V Virtual Switch and any forwarding extensions you have installed are easier to use and read.
Using the new Microsoft Message Analyzer (not just R2) you can also mirror and capture network traffic for remote and local viewing.