The utility used to test server connectivity is just ping. You are repeating the process that Planeshift uses for the same results. Try pinging other sites too. If you are using ping from a business, college, or other entity with a network department, they may be blocking it. You have already mentioned you are not using a router. Also, some dsl modems and cable modems have been known to have internal firewalls which may block it by default. If you cannot ping any other websites, please download your modem's respective guides to troubleshoot them and see which ports they allow. I would also check to make sure OSX isnt blocking the port by default.
