I am facing a problem with an application which uses socks protocol to communicate. My application communicates to server using socks when I am running the application using jre 1.3.1. I have set the system properties socksProxyHost and socksProxyPort which is working fine with jre 1.3.1. Now the problem arises in jre 1.4.1. I get an exception: java.net.SocketException: Socks authentication failed Is there any kind of authentication required for jre 1.4.1? Also is there any other way of communicating to the server by which I can send and receive objects?