401 based authentication
With 401 based Authentication, the Citrix ADC appliance presents a pop-up dialog box to the end user.
Form based AAA-TM works on the redirect messages. However, some applications do not support redirects. In such applications, 401 authentication enabled AAA-TM is used.
Ensure the following for 401 Authentication Enabled AAA-TM to work:
‘authnVsName’ parameter value for the load balancing virtual server must be the name of the authentication virtual server to be used to authenticate users.
‘authn401’ parameter must be enabled. The command for configuring the same is as follows:
set lb vs lb1 –authn401 on –authnvsName
The following steps walk through how the 401 Authentication works:
User tries to access a particular URL using the load balancing virtual server.
- The load balancing virtual server sends a 401 HTTP response back to the user indicating that authentication is required for the access.
- The user sends its credentials to the load balancing virtual server in the authorization header.
The load balancing virtual server authenticates the user and then connects the user to the back end servers.
