If I buy a Iicence L4 for sxt L3 If I receive a lighting strike directly to the router and I need to buy another one I need to buy another licence???? there is some how to migrate the licence to another device if the equipment stop work?
You should never buy licenses for RouterBOARD devices. You have now lost your license.
This is why there exists a separate SXT model that has L4 license built in.
The price difference is less than license price.