Regardless of the type of proxy server you have, you can install the GateDefender unit either behind or in front of it.
However, bear in mind that the GateDefender Performa can update through Proxy servers with Basic, Digest and NTLM authentication, however is not compatible with Kerberos authentications. Therefore, the GateDefender unit could establish a connection through another path without a proxy, or configure the proxy in basic mode.
On the other hand, if client computers have Microsoft Proxy Client and GateDefender is behind the proxy server, it won’t scan the traffic, as the clients will send the data to the proxy server through another port. Because of this, it is advisable to install Panda GateDefender in front of the proxy server.