I am looking for suggestions on how to configure a Mikrotik router to log NAT session setup and ideally teardown. However, setup only is sufficient for my immediate needs.
I found a method to log all packets, and I might be able to reduce this to only logging the TCP SYN, FIN, and RST packets, but I have not yet found that method. This doesn't cover UDP, which I would also like to track. For UDP, it's fine if a session times out and re-appears as a new session again.
You haven't mentioned which method you have found, as standard logging function in RouterOS will not log such info. These information are only available through Connection Tracking, if you meant that, and since Mikrotik doesn't offer any option to export it fully or to send it to remote syslog host, so I guess, there is very little chance to implement what you are trying to.
See this discussion here: http://forum.mikrotik.com/viewtopic.php?t=53483