We're looking for any info or packets that target port 51616.   After witnessing a spike yesterday on his network and checking that our port data [1] corroborated his event, Andrew has written in asking what we know.    

The most useful snapshot of port activity can be seen in this graph image.  I ran the graphs as far back as 2006 and nothing more signifcant was illustrated.   The image below highlights yesterdays events as well as a more curious spike back in March.  These counts do not seem very significant at first look, but they could clearly be telling us something.   

So drop us a comment to share what you know.  We're interested to attribute this traffic to something useful.

[1] https://isc.sans.edu/port.html?port=51616