Nasty little issue here. When you try to mount an ISO to the KVM of a Quanta node you are greeted with this fine message. CD Port: 5120 is only Listening. Closing the CD redirection
Followed by: CD/DVD image redirection failed to start
In order to get your ISO mounted you will need to restarting the cd-media service. Firstly got back to the BMC Main menu. Select the Remote Control Menu then the “Services” sub menu.
You will need to edit the Nonsecure Port number to a non conflicting port number .
I set Port 5128 in this screen shot. Once Complete. Click on the “Modify” button to change the setting.
Once you edit the config and save the changes you get confirmation that the service will be restarted once you click OK.
I would suggest changing the Port number back to the original 5120. You can then mount your ISO. Note you will need to close any KVM session you have open on the BMC.
https://cliffcahill.com 
Awesome catch. This is a pain!
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I agree. Luckily I don’t need to work with quanta anymore
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The services tab is no longer available on newer firmware version of the Quanta servers
Instead if you now go to Configuration>Remote session then set Virtual Media Attach Mode from Auto Attach to Attach and back again to Auto Attach and reboot the remote session it should let you mount an ISO
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