-
I haven't used iApp. If you can explain the functionality, I may be able to answer.
-
You cannot have multiple VS that has the same IP:Port combination. You can utilize iRule or Policy in order to load balance based on Host header.
Example:
domain.com > VS-1 > Pool-domain
domain1.com > VS-1 > Pool-domain-1
In the above cases, VS-1 will send traffic to different pools based on host header and the selection is made using iRule or Policy. iRule is my preference and suggestion as it provides granular control.
3 . If the pool members & the service function are the same for both internal and external service, use same pool. If the pool members or service function are different, use different pools. This is just a guide and it could vary depending on other factors within your environment and function.