Need to access the ESX console with the Virtual Infrastructure Client in some remote location where your VPN does not work. Forward ports 443, 902 and 903 with putty. Port specifics for ESX can be found on page 179 of the ESX Server Config guide.
In my case I additionally need to forward from a boundary machine:
ssh -L 8443:localhost:443 -L 8902:localhost:902 -L 8903:localhost:903 node2