Possible to use the "Un-served License" for a production machine?

Hello!

I am asking this question on behalf of a partner who is trying to set up SMP at a customer site:

One of their clients has 2 Network Cards, in fault tolerance environment (one active at a time), on the Production Machine where SMP needs to be installed. Now, is it possible to use the "Un-served License" for this machine OR "Served License" is the only option?

According to their understanding, Served License does not require the "Host-ID" for the machine where SMP needs to be installed.

Thanks!

Jeffrey