LTM Round-robin

I did a brief testing, and it seems the exact implications of Ctrl + F5 vary across browsers (this may even vary across versions of the same browser). By standard, every web-browser has to omit browser-cache, and seems like all major browsers comply with that, however, on top of that, the Firefox browser opens a new TCP connection as well. That probably is the reason why you're re-balanced when using Firefox, and not in other browsers. As was already pointed out before, the balancing decision by default is made per unique connection that comes in from the clientside. Unless a 'Connection: Close' header is sent from the end-server, that connection (between Browser and BigIP) will be re-used for multiple GET requests. There are a number of possible circumstances that may contribute to different outcomes (i.e. Idle Timeout exceeded). So at least it works as you want in Firefox with the default configuration. With the use of custom configuration, there probably are ways to make Chrome and other browsers behave in a similar way.