I can offer you a solution, if in current configuration this two servers doesnt use port 80 or 443 while communicating to each other.
If they use 80 or 443 to communicate with each other, it is possible to do it too, but it depends on services which are already set on this servers, and need more work.
I am a linux system administrator in data center in Katowice, Poland, I am responsible for almost 400 linux servers, mostly on centos/redhat.