If you play Terraria and would like to run a dedicated server 24/7, just go to www.tdsm.org and follow the instructions there, or use this quick guide that I wrote.
Go to TDSM.org to download the latest Terraria Dedicated Server Client (Terraria_Server.exe). Ignore any possible anti-virus warnings, it is NOT a virus.
Save it in a separate folder, for instance “C:\Games\TDSM”, then double-click to run it.
If Windows firewall asks you, choose to allow access for all networks.
If you don’t have Terraria installed on the server computer, the needed files are extracted to the directory the Terraria_Server.exe file is stored in the first time you run it, and then you need to start it again.
If you’re behind a broadband router, you may need to port forward port 7777 to the IP address of the computer that acts as your server, so that outside n00bs can connect. See example setup screenshot from my D-Link below.
Services like DynDNS are recommended if you don’t have a static IP (meaning that you know for sure that your ISP never updates your IP automatically). I use DynDNS and it works like a charm.
Use whatismyip.com to find your public IP address (or Start-> Run, type CMD, run the command “ipconfig” and see what “gateway” is set to.)
To connect to your own server locally, just use the name of the server computer or local IP. If it is on the same computer as you are playing on, use “localhost”.
You may edit the “server.properties” file (automatically created when you run the server) to configure settings such as port number (default is 7777), password, maximum number of players, default world file location etc. Important: Right-click the file and choose “Open” (or “Open with…”) and choose Notepad as the default editor for this file. It should be one of the available programs in the list.
How to move your existing worlds from your machine to the server:
Open Windows Explorer on your computer. Go to Documents -> My Games -> Terraria -> Worlds. You will see your worlds here, named “world1.wld”, “world1.wld.bak” etc. Copy these files to the “Worlds” folder where the TDSM files got extracted on your server. To change worlds, just edit “server.properties” in Notepad and change the name of the world, save the file, then restart the TDSM server.