> Do your VPSs already have things installed or a GUI?
Nope. I prefer straight-up Arch linux. ssh in and go from there.
To add some concrete-ness to the mix, I was installing ejabberd. When it came time to ping the server... no response. I did the exact same steps on my Digital Ocean VPS and everything went fine. I had done whatever commands EC2 expects to open the right ports...