Inchoate Curmudgeon

While looking for an OS X alternative to the ESX Virtual Infrastructure CLient for accessing the console of a virtual machine hosted on ESX, I found this article. An example configuration for accessing the console for a client on the ESX server using VNC port 5901 using a password of “secret” would require adding the following entries in the .vmx file for the virtual machine.

RemoteDisplay.vnc.enabled = "true"
RemoteDisplay.vnc.port = "5901"
RemoteDisplay.vnc.password = "secret"

The instructions work for ESX, except for one small detail: the ESX server won’t accept remote VNC connections. There is likely some way to turn this on, but allowing remote vnc connections to a server is typically not allowed and is considered a security hazard.

The solution is too use ssh port forwarding. If the vnc port on the ESX server is 5901, you create a tunnel with the following ssh command:

ssh -L5901:localhost:5901 user@esxhost

where “esxhost” is the hostname of the esx server and “user” is an authenticated user on the esx host.

Once logged in, you can connect to vnc port 5901 using any vnc client on the ssh client machine you have just connected from. The host should be “localhost”, the port should be “1″ and the password should be “secret”. The console for the client on the ESX server should be displayed. My vnc client of choice on OS X is “Chicken of the VNC” but here are many alternative vnc clients for OS X and other operating systems.

Note that ssh is disabled by default for root on ESX server, so if the “user” for ssh access is root, you will either need to enable root access by editing /etc/ssh/sshd_config on the ESX server and set “PermitRootLogin” to “yes”, or use another user authenticated on the ESX console. The later method is more secure since enabling root ssh access to the console is inadvisable for production installations.