When a custom site name is used to establish a connection to NetScaler through Receiver with NetScaler Gateway version 10.x or above, the following error message is displayed:
The gateway setting is invalid.

To resolve this issue complete the following step from the NetScaler console:

set vpn sessionaction <session-action-name> -clientlessvpnMode OFF -transparentInterception OFF

<session-action-name> would be the name of the Session Action // Session Profile you want to modify. It can be found in ttwo different ways:

• From the NetScaler Gateway Virtual Server that is experiencing the issue: Netscaler Gateway > Virtual Servers > Edit the corresponding virtual server > Session Policies:

• List of all the Session Action // Session Profile configured: NetScaler Gateway > Policies > Session > Session Profiles:

After completing the preceding step NetScaler Gateway will respond with setclient?wica (instead of setclient?iosc) as expected.

Problem Cause

NetScaler Gateway version 10.x and above includes a modification in the transparent interception proxy configuration. When using a customized site name, NetScaler declines WICA mode and prevents the connections from using a PNA style connection.