Licensing of Active Passive Software

Hi,

I'm trying to figure out how to set up licensing for an active passive solution.

I have two bare Servers on which I want to intall the UTM9 Software.

One of the boxes is just for failure purposes and in case the first one breaks it should take over operations.

To my knowledge I only Need one Software license for that. But how do I set up the second box without a license at all!?

I haven't bought a licensee yet, just trying to figure out the best and cheapest solution for this.

Thanks,
Chris