Using LTM as a reverse proxy

My environment is as follows:

 

I have a pair of 3600's in a DMZ and a pair of 6800s internally. I have OCS CWA webservers sitting behind the 6800s. The web servers have 2 https IIS Virtual servers, one for internal users on 443 and one for external users on port 90.

 

I need users to be able to connect to the external 3600 CWA VIP, and then hit the internal 6800s and go on to the CWA servers.

 

I have set up a VIP on the 3600. The virtual server has a service port of 443, it is also using clientssl and serverssl profiles. It is assigned a pool with one member, the internal CWA VIP on the 6800s on PORT 90. The internal virtual server is assigned a pool which contains the CWA web servers on PORT 90.

 

When I type in the external URL, it connects to the website, but takes a very long time. Then it finally brings up the login screen for CWA but no pictures or icons are visible. I can log in but everything is so slow it is unusable.

 

The issue stems from changing the 443 to port 90. If I leave out the external pair of F5s and just use the internal F5 to accept traffic on 443, and send it to pool members on 90, I get the same behavior. IF i connect on port 90 internally without changing it from 443 to 90, so https://cwa.domain.com:90, it works fine. Any ideas on what could be happening?

 

Thanks