Try to access auth.blockland.us on the network/machine that you are hosting with.
Are you hosting the server on the same computer, or network, as your client?Try connecting locally. If it's a single computer, just connect to 127.0.0.1, otherwise, connect to the local IP.
Try asking someone else to join the server. Have that person check their IP address and then compare that address to the one that shows up in your console log. The auth system works by sending the player's name and IP address to the auth server, and then the auth server replies YES if the IP sent matches the IP the auth server has stored for that player's last client authentication (This is why you get kicked out of servers if your IP changes while you have Blockland open). Auth will always fail if your server is receiving an IP address that is different from the real IP address of the person trying to connect, this might be caused by a non-transparent proxy server.
ISP? I'm trying to narrow it down to a singular problem ATM
I'm in Singapore, so you won't recognize my ISP. It's Singtel.