Persistence is a feature that is required by many web applications. Once a user has interacted with a particular server all subsequent requests are sent to the same server thus persisting to that particular server. It is normally required when the session state is stored locally to the web server as opposed to a database.
IP based persistence:Â This is a simple method but is not very effective due to the â€œsuper proxiesâ€ i.e. a user could connect to the site via a range of external IPs thus breaking the persistence.
Cookie based:Â Layer 7 devices can take advantage of setting a load balancer cookie with the persistence information. This is a more reliable method and does not suffer from the super proxy problem.