Hi
When sending the redirect back to the client, the client will initiate a new connection to a new destination. --> Server1 or Server2 Therefore no control over the connection within this irule anymore.
I think you now found the issue, that you would not reach the server 1 or 2 if it is down.
So i do not think you should work with redirect at all. Do you have control over those servers ?
Why do you need to work with a redirect ? Just Loadbalance the Servers with a pool and replace the hostheader if needed. (don´t think you need to)
Please explain us about the goal of the redirects a bit more that we are able to help
Wiesmann