VMWare COM port forwarding issue - vsphere 6.0 and windows 7 guest.

VMWare COM port forwarding.  

We have a customer with an Opera IFC server which was on a failed vSphere 5.5 host.  I've rebuilt the host and lit all the VMs back up on it.  However, their opera interface can no longer communicate with the vm.  I then realized that 1 of the 9 IFC connections (the one that isn't working) is RS232 serial, so I added the uart0 from the host to the VM.  I rebooted the VM and COM1 and COM2 ports show up.  I thought all that was over with, but now the customer is telling us that the Aloha system hasn't worked since the rebuild.  I rebuilt the VM host using vsphere 6.0.

To test, we plugged a known working loopback adpater for the serial port and tried establishing a connection.  The port immediately closes the session and says the COM port is not ready.  

I'm using UART0 on the vsphere host and I'm using COM1 on the IFC vm.  I've not changed any of the settings on the VM from adding the COM port.  This should just work, right?  

FYI- I'm currently awaiting a window in which I can reboot the vm.  Unfortunately, there are 8 other interfaces which must remain up as this is hospitality.  

Thanks in advance!

LVL 16
Chris HInfrastructure ManagerAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
did you check in the VM BIOS the ports are enabled ?

also COM1 is available in the VM device manager ?

As a side note, we've always had major issues with COM ports in ESXi, and there moved to USB/RS232 Serial ports, which create a phamton serial port driver in the OS.

and use USB Passthrough.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Chris HInfrastructure ManagerAuthor Commented:
Awesome!  Can you provide a link of the last one you bought that successfully worked?  

THanks in advance!
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
The ones we use are very common, often called FTDI 232 USB to Serial adaptors.


I believe FTDI are the sole manufacturers of these USB to Serial Adaptors.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.