The NetScaler
appliance uses backup persistence to choose a new type of persistence when the
primary persistence type fails. For example, if the primary persistence type is
set to Cookie Insert, and backup persistence is set to Source IP, the NetScaler
appliance uses Source IP-based persistence when the cookie is missing from the
HTTP header or when the client browser does not support cookies.
You can set a
time-out value for backup persistence only when the primary persistence type is
HTTP Cookie-based or RTSP session ID-based persistence, and the backup
persistence type is Source IP-based.