HTTP requests in persistent TCP connection routes traffic to the disabled server

Thanks for your quick response Alfro. We are aware of how persistence works with Cookie Insert model and that is the reason we are manually clearing the cookie in iRule during logout request. But LTM routes the next login request to the same disabled server even though the cookie BigipServerMy_PoolName is not present in the login request. This behavior happens only when the login request in sent in the persistent TCP connection established on or before logout. If there is no persistent TCP connection available when we click on login, browser establishes a new connection to LTM and the request is properly load balanced to an active server. We want persistence connections to continue to go to disabled server till the user logs out and logs in back. Clearing cookies will not help as the behavior is dependent on persistent TCP connections and not due to cookies. We also have an iRule to clear cookies, but LTM is not considering that cookie (whether it is present or not) when the request is sent through a persistent TCP connection opened before clearing the cookie. Why the behavior is dependent on persistent TCP connection between the browser and LTM? How to enforce LTM to load balance the request if BigipServerMy_PoolName is not present in the request (irrespective of whether the request is made through a new TCP connection or an existing connection)?