Andy Hall

After Win10 update, connection between pair of Win 10 PRO 64 machines failing

10 posts in this topic

I have a pair of Wondows 10 Pro 64-bit machines which have been successfully running Synergy V1.8.8 since Mar. 3, 2017 and older versions prior to that.  Both machines have revently receieved the now infamous Windows 10 Update KB3150513 (4 times starting 5/23!).  SInce then, I have had continual problems with gettting the client to connect to the server, expecially when I come out of power save mode on both machines.   Its looking more and more like some sort of forewall issue.   The client pounds away trying to cennect evey 15 seconds, and eventually connects (>30 minutes!)  During this time there is this SYN sent request on the client.

  TCP    192.168.1.140:50368    104.25.249.12:80       ESTABLISHED
 [synergy.exe]
  TCP    192.168.1.140:50370    192.168.1.125:24800    SYN_SENT
 [synergyc.exe] 

When it finally connects,  the server shows this:

 $ netstat -an | grep 2480
  TCP    0.0.0.0:24800          0.0.0.0:0              LISTENING
  TCP    127.0.0.1:24801        0.0.0.0:0              LISTENING
  TCP    127.0.0.1:24801        127.0.0.1:49731        ESTABLISHED
  TCP    127.0.0.1:24801        127.0.0.1:49967        ESTABLISHED
  TCP    127.0.0.1:24801        127.0.0.1:50230        ESTABLISHED
  TCP    127.0.0.1:49731        127.0.0.1:24801        ESTABLISHED
  TCP    127.0.0.1:49967        127.0.0.1:24801        ESTABLISHED
  TCP    127.0.0.1:50230        127.0.0.1:24801        ESTABLISHED
  TCP    192.168.1.125:24800    192.168.1.140:50768    ESTABLISHED

and the client shows this.

 TCP    127.0.0.1:50366        127.0.0.1:24801        ESTABLISHED
 [synergy.exe]
  TCP    127.0.0.1:50367        127.0.0.1:5354         ESTABLISHED
 [synergy.exe]
  TCP    127.0.0.1:50371        127.0.0.1:24801        ESTABLISHED
 [synergyc.exe]

Is it correct that I do not see a connection to the server (192.168.1.125) when Synergy is working?

 

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There should be no reason that it won't connect. Have you tried doing a network reset on both machines @Andy Hall?

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I was wrong about the client machine.   When it finally connected this morning (about 30-60 mins), netstat shows 

 TCP    192.168.1.140:51048    192.168.1.1:9393       TIME_WAIT
 TCP    192.168.1.140:51052    192.168.1.1:9393       TIME_WAIT
 TCP    192.168.1.140:51059    192.168.1.1:9393       TIME_WAIT
 TCP    192.168.1.140:51060    192.168.1.1:9393       TIME_WAIT
 TCP    192.168.1.140:51061    192.168.1.125:24800    ESTABLISHED
[synergyc.exe]

Which is what I would have expected.   Oddly, 192.168.1.1 is my gateway.   I wonder if I am having DNS/router issues.

I will try resetting the network the next time I come out of power save mode and am stuck as described above. 

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Yes.  But I don't totally trust Win 10 netstat. I looked at my router and I can't see any evidence of a connection / blocked connection on port 9393.. Weird. Client netstat is now showing just an established connection to the server.  That you would expect when the connections in TIME_WAIT finally time out.

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We can only guarantee the server to use port 24800 since client machines doesn't have a configuration set on it. It relies on the configuration on the server machine. So having a different port number on the client machine is totally fine.

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Lets not get diverted by the connections from 92.168.1.140:510xx to my gateway that are in TIME_WAIT. These may be the residue of attempts by processes other than synergyc.exe to establish a connection.   However,  it is odd that the port numbers happen to be so close to the one finally used in the ESTABLISHED connection.   Keep in mind that the that client is trying to establish a connection every 15 seconds and timing out.  That behavior results in the connection going into the TIME_WAIT state.

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@Andy HallPort 9393 isn't one our ours, so no idea about that. Port 5354 is the port used by Bonjour for autoconfig, so that connection is between our GUI and the Apple Bonjour service. Port 24801 is the port used by our service for IPC between the core, service and GUI.

Hope that helps

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I am going to defer trying a network reset until I get some resolution from MS on the excessive CPU issue. When that subsides, synergy happily connects.   Network reset in W10 is a bit of a sledge hammer.. Removes and re-installs the network adapters.returning them to the original settings.  I then have to re-install any VPN adapters which I just did yesterday..

This is almost certainly a W10 firewall issue.  

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I  have found the culprit!    Around 5/23/17 I happened to run a program from TrendMicro called "House Call for Home Networks"  as a demo for a friend having trouble.  At or around this date is when I started having this problem.

Suspecting "House Call for Home Networks" was the culprit, I uninstalled it, but that did not help. 

Yesterday, noting that the problem described above involved the Firewall (not able to make connections from remote machines), I decided investigate the Firewall configuration in depth.  

I found that "House Call for Home Networks" had created 4852 rules out of a total of 5218 in the Inbound Rules Table. This seemed very wrong.  I have reported this in detail to TrendMicro.

Unfortunately, as of this morning I could not restart the system in question in normal mode as it seems to have gone south after a failed W10 update (possibly the Creators Update)  I could start it in Safe Mode, but was unable to find a way access the Firewall Advanced UI in Safe Mode. 

This afternoon, I managed to launch the Firewall Advanced GUI in Safe mode. You have to run the .exe as administrator from the list of admin tasks not via the UI. I removed all 4852 rules related to House Call.  I wasn't fast.   I also had to reinstall my graphics driver, but when the system came up there was no high CPU and the synergy client connected instantly.   

This was really ugly.   This is so specialized I think the whole tread should be deleted.  It won't help anybody.with Synergy and it wasn't due to the Windows update.  That's a false lead.  

But there is a bug in the Windows firewall.  It should not allow duplicate entries to be created. There were several other very small instances.

Thanks for you help and patience.

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