unique identifiers of a VPS

I am trying bind my application just to my VPS.

Can you please tell me about some identifier that each VPS has unique? Ideally something that can be determined by command in开发者_如何学JAVA Ubuntu server.

Thanks in advance.

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Three things come to mind.

1. MAC Address
2. Public IP Address
3. Fully Qualified Domain Name of the host.

Any of these three, or all three combined, should assist you in determining which node is which.

These things are not limited to a VPS, either, so a method utilizing these parameters should also work on physical hardware.