To enable ssh on the host with esxi 5, you can use two ways.
1. Turn on the console ssh host esxi.
You just need to go to the Host Configuration tab and “Troubleshooting Options” select “Enable SSH”.
2. Enable ssh through vsphere client.
Go to the Configuration tab in the vsphere client, further in Security Profile select Properties, select SSH – Options, “Start and stop with Host”, and start by pressing “Start”.