“Unable to connect to the MKS”: the port 902 problem.
Posted by jpluimers on 2016/05/23
A message like “Unable to connect to the MKS” usually does not mean you have reached the maximum of 10 connections for a VM.
Usually it means there is some network issue, like a firewall or router misconfiguration.
Port 902 is used (both TCP and UDP) to provide (among others, hence MKS) console connections.
The default MKS port is 902, and you cannot change it.
For vCenter it is even worse as you cannot even go through NAT:
- nat – Connecting to vCenter Server, Unable to connect to the MKS: Failed to connect to server xxx.xxx.xxx.xxx:902 – Network Engineering Stack Exchange.
- Accessing VM Console – Error 902 – [H]ard|Forum.
About the only solution is to tunnel through SSH: VMWare vSphere Client Remote Access via SSH Tunnel and redirect ports 443, 902 and 903.
–jeroen
via:
- VMware KB: Opening a console to a virtual machine fails with the error: Unable to connect to the MKS: Console access to the virtual machine cannot be granted since the connection limit of 0 has been reached.
- nat – Connecting to vCenter Server, Unable to connect to the MKS: Failed to connect to server xxx.xxx.xxx.xxx:902 – Network Engineering Stack Exchange.
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