Since the Xplane 11.10 update and continuing in the 11.11 update my networked system has not functioned properly. Basically, without the intervention described below,

the slave system does not receive the data sent by the master.  

The master system is an I7 running Win7 and is used to display the default C172 3-D cockpit view zoomed and moved to display just the panel.
The slave machine is an I7 running Win7 with a GTX1070 driving 3 monitors for external scenery view.  

The X-plane systems have identical resources. There are no firewalls and no antivirus.  System File Checker has found no Windows file integrity problems.
The system is not overclocked.

The networked PCs connect via a Netgear 10/100 Switch. The network is properly configured, all static IPs double checked, and sharing and permissions are
in place. Each PC "pings" correctly and files can be read, moved etc etc.

The Xplane network is configued properly through "Settings" as Master and External Visuals and the PC Names / IP entries are correct.

Xplane starts properly on both PCs but the lack of contact can be confirmed by looking at "Network" in the Settings on both PCs
The Network panel on the Master shows that data was sent to the Slave "just now" while the Slave shows "data received x seconds ago" with x counting up to
60 seconds and which time it shows "no incoming data". 

In an effort to resolve the issue I have
- removed all plug ins 
- deleted xplane.prf and miscellaneous.prf from Output - Preferences.  Restarted and re-set preferences several times just hoping for an Xplane miracle.
This did nothing to fix the network issue.

There is nothing remarkable in the Master Log.txt or the Slave log.txt. Both have appropriate I/NET: Local Area Connection entries.

The only thing the "works" is to disconnect either or both PCs from the switch and then reconnect the cables. At this point the slave receives data and away we go.

Has anyone seen anything like this? ..... any suggestions would be most appreciated.

Greetings from warm and sunny Melbourne, Australia. (36*C yesterday, 31*C today)
Bob

I recently just updated our lab's simulator and am encountering this same issue. However, disconnecting either of the PCs does not resolve this issue. 

Hi coletr

I tried so many things to get my networked sim system working properly again and it seems to be stable (sort of) once again. The last thing I did was so factory reset my modem and then reconfigure it. Your mileage might differ but it seemed to work for me. Good luck!!!

Aussibob