What is proper way to stop irule processing when F5 is behind Akamai CDN

Any HTTP requests routed via Akamai CDN come with "Via" Header that contain 'akamai' sub-string in it. Therefore, for HTTP services you can use my iRule as a starting point. You can similarly just start with the functionality right after the Via header value check, but if you have more bypass conditions, such as some monitoring server IPs, using a variable could make your code look better visually.

I use similar logic

when HTTP_REQUEST {
  set byPass 0
  if  { [HTTP::header value "Via"] contains "akamai" }{
     Replace akamai with llnw if you use Limelight
    set byPass 1
  }

  if  { $byPass == 0 }{
     Do whatever you want here
  }
}