Sorry for bumping such an old thread. I was curious if there is a workaround for this. I use a VPN to log in to work and once I do that it prevents me from streaming to my airport express or my apple tvs. My PC that I log in to the VPN is the one that runs iTunes. I have a 1TB external USB drive hooked directly to that PC that contains my music. I am curious if there is anything I can do with the setup of my PC so that streaming is still available when logged into my work VPN. Or, if I should look into an alternative means of streaming for my external drive such as a NAS running iTunes.
Thanks in advance.