Enforced redirects in F5.

I have several websites that are external facing that are windows authenticated (Kerberos). We are using Okta for authentication. When the user is authenticated in Okta, it creates a Kerberos token which it passes to the sites for authentication. I am adding a new site that I want to make sure that all users visit first - we'll call it SiteMain. The others we'll call Site1, Site2, etc. So when a users is trying to get to Site1, he should be sent to SiteMain first. When SiteMain has done it's thing, they should get redirected to the intended site. We have accomplished this using a combination of forms auth and windows auth in a small dev environment but sitting behind the F5, we are having problems.

 

The question is this. Can the F5 do this sort of thing or will we need to take other steps to accomplish this?