Anything that asks for something via localhost fails. I can't get any result from pinging localhost. The only way I can reach anything in my network would be to resort to connecting to my externalIP:port# and that will route myself back in. My host file seems to look ok... How can I fix this?
Are you 100% sure your host file is correct?
If ping is giving you Unknown host that means it doesn't have that info on the host files or any thing to resolve to localhost being your computer.
Open a terminal window
Type in sudo pico /private/etc/hosts
Check if you have something like this
If you don't have this lines (which you probably don't by the result of your ping) then your host file is not ok.
You need those lines, specially the first one to be able to resolve to localhost.