Comment 24 for bug 207456

benc is right: on Linux, Firefox now responds to dbus messages from Network Manager, which means that if you disconnect the network cable, Firefox goes offline and you can't access your locally-served resources.

I think an exception for 127.0.0.1 and localhost would cover 99% of the cases. We could even make the list of exceptions a pref for the tiny number of people who have other local aliases for their own machine.

Gerv