I have just a single domain. I have 1 reverse proxy (l7 load balancers) and 3 webservers serving www.example.com
I am getting an ssl pro certificate for the domain and I want to understand the number of licenses I will need.
Let's assume that self-sign cert is out of the equation for the entire path between
client <-> lb <-> webservers
choice 1) cert on loadbalancer only, communication between loadbalancer <--> backend webserver is pure http.
choice 2) cert on loadbalancer, cert on webservers
client <-> lb <- webserver> all https
For choice2, can I just use 1 cert and install the same cert+ptvkey+intermediacert on the loadbalancer and all the webservers?
Is the number of licenses required for a domain a pure commercial restriction or are there really some technical parameters in the cert itself that restrict the no of servers that can use it?