Assign different IP addresses to different applications (one of which is Plone)

I have a situation at work that requires that I assign different IP addresses for different applications on the same Linux (Ubuntu) box. One of the applications concerned is Plone. I have two servers. One is the web server and the other is the data server. The connection between the web and the data server can be just IP address. What I need is to have different IP addresses for different applications from the front-end (web server). Does anyone have any advice as to how I should go about with this? Any advise would be most appreciated.

this is completely out of topic, anyway:

Ask your system administrator.

Thanks guys! So where Plone is concerned, is there anything different that I need to do? So if there are two IP address going into the same box such as:

And if I want to go to Plone only, do I replace below with

<IfModule mod_rewrite.c>
  RewriteEngine On
  # serving icons from apache 2 server
  RewriteRule ^/icons/ - [L]
  RewriteRule ^/(.*)$ balancer://zopeInstances/VirtualHostBase/https/%{SERVER_NAME}:443/VirtualHostRoot/$1 [L,P]
  <Proxy balancer://zopeInstances>

You have to set the ˋhttp-addressˋ in your Plone configuration to a dedicated ip:port and use these in your Apache or loadbalancer configuration. It is obvious what to replace in your given configuration.

Thanks so much, Andreas. It is much appreciated.