Simulating another network

We are looking for a better way to troubleshoot issues when assisting customers that contact us from off-campus here at a university that I work. The reason for this is we have certain services (such as one research tool known as Galileo) that only prompts for a password when a user is off-campus. When on campus you are able to access all resources, as I believe it validates the computer based on IP address. It is difficult to assist someone when they are unable to login because employees here on campus can access the Galileo resources without validation.

We have tried using various anonymous web browsing websites but these do not consistently work. Does anyone know of an application or reliable websites with a reliable "proxy" service?

Thanks!