llnwd.net is a domain used by customers of the Limelight Networks content distribution network (CDN), they host content such as downloads and streaming media for companies like EA Games, BBC and Microsoft. You will probably notice a lot of internet traffic going to this domain, that is because it hosts streaming content etc.
Limelight Networks is a premier content delivery network (CDN) service provider that enables organizations to deliver faster websites, more responsive applications, the highest quality video, and consistent game and software downloads to any device.