We currently run 4 onsite web servers and 1 offsite server. Four of our severs run Apache 2.x webservers, while the one other server runs Tomcat.
The server which runs on Tomcat contains third party software, and we can't change it to Apache.
We have one domain name, and several subdomains pointing to each of the servers. For instance:
sd1.domain.com - Apache Server - Windows sd2.domain.com - Apache Server - Windows sd3.domain.com - Tomcat Server - Windows sd4.domain.com - Apache Server - Linux
As you can see (in my crude example), although the server software changes, the domain name still points to the servers.
My question is, we are looking into purchasing a wildcard/multi-server SSL certificate. Will I only need to purchase one certificate for all servers, two certificates for windows/apache or three certificates for apache/tomcat?