Forum Discussion
it might sound unkind but did you do any research yourself between when when the requirement changed again and now? this is pretty common question and has been answered many times.
first I would like to echo the remark by Odaah, all this tinkering is not helping the application in the long run. it would be better to just rebuild it like it should work then keep adding tricks in front of it, specially if you need other people to make it work.
then towards an answer, if this is possible depends largely on how the system is setup. is this all behind one virtual server with different named hosts behind it in one pool?
if so then the HTTP Host header and URI can be modified to send the traffic with a different setup to the backend server(s) and might be handled correctly. things can get more complex if the website contains links to the original website that don't work now. with mulitple pools it might still be possible, also select a different pool. if the target servers are not behind the F5 then it becomes really challenging and i would just go with the redirect.
some example for the incoming traffic can be found here, they will require some tinkering for your situation though:
https://devcentral.f5.com/questions/replace-part-of-irule-and-irule-applied-doesnt-work-47775
https://devcentral.f5.com/questions/need-to-replace-part-of-uri-in-url-tried-many-irules-47743
the proxypass irule might also be an option, it is framework to handle rewriting for incoming and outgoing requests.
https://devcentral.f5.com/codeshare/proxypass-v10-v11