DDO requires access for both incoming and outgoing data via your router. Specifically two files will need to be permitted for Dungeons and Dragons Online. These two files are dndclient.exe and dndlauncher.exe. Both of these files need to have full permission in the firewall to access the servers.
Ports which need to be open: 80, 9000-9058.
For assistance with configuring your software firewall, please contact the manufacturer. Below are listed some of the major software firewall providers for your convenience.
- Zone Alarm: http://www.zonealarm.com/
- Norton/Symantec: http://www.symantec.com/index.htm
- McAfee: http://www.mcafee.com/
- Windows Service Pack 2 Firewall: http://www.microsoft.com/windowsxp/default.mspx
Also it should be noted you may NOT need to configure your router on certain operating systems such as windows 7 which will ask you to set the rule of permanent access when first running your client after a fresh game installation (and sometimes after game updates. patches, maintenance or hotfixes).