Forum Discussion
Those questions may actually be related. Each ASP.net application can set it's own SessionId. say you have 1 application deployed in https://www.site.com/documents and another deployed in https://www.site.com/hr you may end up with multiple ASP.net cookies which could lead to persistence issues. Also each ASP.net application can remove or change the cookies so you may have one application that removes the SessionId, it will be regenerated for the other applications but that may cause perisstance issues.
If you are using a traffic policy (or an iRule like proxy pass) to load balance to different pools via url path or other criteria the F5 cookie option is also nice because F5 will insert a new cookie for each pool name - SOL6917: Overview of BIG-IP persistence cookie encoding
If I were to choose, I would always use the F5 cookie insert because it is a known entity and not externally controlled. On the other hand, it is nice to know when a session no longer needs to be persistent because the SessionId has been removed since the cookie insert is session based.