Landing

I didn't see a section in your iRule that looks like you're trying to send certain traffic to a maintenance page. I did find a couple of links that may be helpful if you are trying to create such a redirect. The following links show how to match on the HTTP::host and redirect accordingly. The second link is a helpful example of how to redirect all subdomains of a particular domain.

https://devcentral.f5.com/questions/httphost-and-if-match-redirect-by-using-httpredirect

DevCentral: Match all subdomains of a domain