What they do not mention is that this feature only works in VMware Enterprise licenses.
I spent hours trying to figure out why my serial port would never maintain its "Connected" checkbox as shown below:
It would consistently revert and I had already confirmed that firewall was not blocking the ports:
~ # esxcli network firewall ruleset list -r remoteSerialPort Name Enabled ---------------- ------- remoteSerialPort true
I have also verified that the esxi server is accepting connections to 3008 on the host:
telnet RPC-D8-03VM 3008 Trying 10.129.36.2... Connected to RPC-D8-03VM.phaedrus.sandvine.com. Escape character is '^]'. test testing ~ # nc -l 3008 test testing
But nothing seemed to work. Even new version of virtual hardware/different OS.
lspci wasn't showing anything even being connected to the guest.
After contacting VMware support they looked through some logs and noticed the following line stating this feature wasn't licensed:
2013-11-25T17:53:07.636Z| vmx| I120: Msg_Post: Error 2013-11-25T17:53:07.636Z| vmx| I120: [msg.serial.uri.nolicense.basic] The currently available license does not permit the use of remote serial ports.
Due to this licensing issue the VM will not even attempt to add the virtual serial port and you will not be able to telnet to your serial port or use a virtual serial port concentrator without an Enterprise license.
For future reference the log that told us that this was not a licensed feature was:
The fact that the GUI does not give any kind of notification of this functionality not working is a bit disappointing, but not more so than the functionality being licensed and not being usable.
References to others having this issue: http://community.spiceworks.com/topic/247096-virtual-serial-ports-in-vsphere-esxi-5