Maintenance Page redirect

You can definitely serve the maintenance content from a VS on the BIG-IP, and the content can contain a timing element that will cause the client browser to refresh the page. See this link for an iRule example: https://devcentral.f5.com/wiki/iRules.LTMMaintenancePageLite.ashx

 

You would need some way to distinguish between the first time a client attaches to the virtual server and any subsequent connection, but an HTTP cookie would probably accomplish this.

 

Borrowing from the listed exampled, it might look something like this:

when HTTP_REQUEST {
    set mainttime "10:00pm Eastern"
    if { not ( [HTTP::cookie exists "maintbanner"] ) } {
        HTTP::respond 200 content "Maintenance AlertThis site will be going down for maintenance at $mainttime. Please complete your session and logoff before then." "Content-Type" "text/html" "Set-Cookie" "maintbanner=1"
    } 
}

I'm setting a cookie in the maintenance splash page, so that after the refresh it'll bypass this for the rest of the session.