Okay, so this is more of a minor annoyance than an actual problem, but my loopback interface doesn't seem to be working. I would like to understand why this is, and maybe figure out how to fix it. When I ping 127.0.0.1 I get a request timeout message, which means the loopback interface is not responding to echo requests. What sort of problem would this indicate, and how can I fix it? When I run ifconfig, it shows that the loopback interface (lo0) is up, so clearly the driver for it is loaded. I'm using a Macbook connected to the Internet through WiFi, if that's at all relevant.