RCI Error: cannot open port #1055. Probably port in use

eljefegt · Post by **eljefegt** » Tue Jan 17, 2017 9:32 pm

Occasionally in our environment, we find an issue where we're unable to log on to RCC. I believe this also prevents tests from reporting properly, but I haven't been able to confirm that 100%. The only way to correct the issue is by rebooting the server, which is an issue as this is in use in a production environment.

RCC Log shows:
[1/17/2017 9:18:42 PM] Connecting... Ok. TCP Connection established
[1/17/2017 9:18:42 PM] Authentication... Failed. Cannot read data

HostMon SysLog around the time of the error shows: (We attempted to restart the service a few times)
1/17/2017 8:55:47 PM Action error: Attachment file not found (D:\HostMon\ESO\Scripts\output\%TestName%\%NewestFile%)
1/17/2017 8:55:47 PM Action error: Attachment file not found (D:\HostMon\ESO\Scripts\output\%TestName%\%NewestFile%)
1/17/2017 8:58:00 PM Action error: Attachment file not found (D:\HostMon\ESO\Scripts\output\%TestName%\%NewestFile%)
1/17/2017 8:58:45 PM Action error: Attachment file not found (D:\HostMon\ESO\Scripts\output\%TestName%\%NewestFile%)
1/17/2017 9:04:23 PM Action error: Attachment file not found (D:\HostMon\ESO\Scripts\output\%TestName%\%NewestFile%)
1/17/2017 9:06:05 PM Monitor started
1/17/2017 9:06:05 PM RCI Error: cannot open port #1055. Probably port in use
1/17/2017 9:06:06 PM Error: cannot save log list.File access denied
1/17/2017 9:15:40 PM Monitor started
1/17/2017 9:15:40 PM RCI Error: cannot open port #1055. Probably port in use
1/17/2017 9:15:41 PM Error: cannot save log list.File access denied
1/17/2017 9:16:15 PM Monitor started
1/17/2017 9:16:15 PM RCI Error: cannot open port #1055. Probably port in use
1/17/2017 9:16:15 PM RCI Error: cannot open port #1055. Probably port in use
1/17/2017 9:17:04 PM Monitor stopped
1/17/2017 9:17:07 PM Monitor started
1/17/2017 9:17:07 PM RCI Error: cannot open port #1055. Probably port in use

When I attempt to force close the port with a tool like cports, the port cannot be closed. I read multiple threads around StackOverflow about this essentially being a zombie process holding the port open.

netstat -ano shows the port open and assigned to a process that doesn't exist in task manager.

Any ideas what could be causing this?

KS-Soft Europe · Post by **KS-Soft Europe** » Wed Jan 18, 2017 4:01 am

CurrPorts shows that TCP port 1055 is used by System process.
That's why HostMontor can't open TCP port 1055 for incomming connections.
You may change TCP port, used for RCI connections (RCC, Telnet, Web Service) using HostMonitor menu Options -> RCI. Do not forget to change connection port on RCC/Telnet/Web Service clients.

eljefegt · Post by **eljefegt** » Wed Jan 18, 2017 9:52 am

I don't believe we have anything else that should be using port 1055. Is there any instance in which an orphaned RCC session could show up as System process?

KS-Soft Europe · Post by **KS-Soft Europe** » Wed Jan 18, 2017 10:59 am

No. TCP port 1055 (used by default) should be opened for incoming connections by hostmon.exe process.

KonstantinK · Post by **KonstantinK** » Thu Oct 06, 2022 7:28 am

Hi, Friends.

I'm using version 12.98, and I've had the same issue.
It happens on the computer with Windows 10.

The message appeared when the HostMonitor service was closed, and the Application started manually.
After a short investigation, it became understood that the previous process had closed and the port had been left open.

Nothing except restarting the computer didn't help.

KS-Soft · Post by **KS-Soft** » Thu Oct 06, 2022 8:48 am

Try to use port above 5000

Regards
Alex