Why are there multiple ways to set cookie peristence for ASP.NET Forms authentication? Each of the following related methods [1] allows you affect the cookie expiration period.
FormsAuthenticationTicket Constructor
FormsAuthentication.GetRedirectUrl Method
HttpCookie.Expires Property
[1] For example, consider the following sequence of related operations:
Create an authentication ticket (FormsAuthenticationTicket)
Derive a cookie from the ticket (FormsAuthentication.Encrypt)
Get the redirect URL (FormsAuthentication.GetRedirectUrl)
Set the cookie (Response.Cookies.Add(cookie) )