How to Configure Monitors in NetScaler
Citrix NetScaler uses monitors to track the state of back-end servers.
Some back-end servers behind the NetScaler may request that all communication be done after presenting a user name/password. By default, the monitors in the NetScaler are not configured to present a user name and password.
In situations where back-end servers function as described previously, the HTTP, HTTP-ECV, or TCP-ECV monitors are denied access.