We have a problem for which I cannot find the cause...
From time to time (quite often) we have a situation where NAV2013 R2 clients could not login to NAV while active connections on that tier are working ok. This is going on until NST is restarted. In period when clients could not create new connections there is no error events in event viewer except large number of information events on Security, event id 5152, WFP blocked packet on port 7046.
I've search on this event id and found that it is a part of windows filtering platform where Windows blocks packet to certain port even if that port is opened in firewall (or firewall down) for a reason that no service is listening on that port, thus preventing port scanning (this is called windows stealth mode, working separately of windows firewall). Since existing NAV connections are working properly, I can say that port 7046 has a listening service so I'm stuck, why would windows block this packet if port is opened and service is working.
I have checked Max concurrent calls and Max Concurrent connections setup on NST and it is set way beyond number of users.
Windows 2012 R2
NAV 2013 R2 with CU 10
Three instances in use, one client and two NAS.
No separate AV installed.
This happens from time to time, but usually when there's a lot of users already connected (50+).
Does anyone has idea what could be the cause for this to happen?