Cookie sharing under cluster, must be set machinekey

This section allows you to set a server-specific key for encrypting data and creating a digital signature. Asp. NET automatically uses it to protect form validation cookies, which you can also use for Protected view state data. At the same time, this key is also used to validate out-of-process session state providers. If you are using a Web cluster and running the same application on multiple computers, if the request to the page is handled by one computer, and the page postback is processed by another computer, the second server cannot decrypt the view state and form cookie from the first server. This problem occurs because the two servers use different keys. To solve this problem, you must explicitly define this key in the Machine.config file:

</>

Cookie sharing under cluster, must be set machinekey