You've built the lwIP stack on your target, gotten your network driver working and hurray! you can ping your device!! Great, congratulations to you. A device that can respond to a ping isn't good for a whole lot though. Now you'd like to actually do something with the network interface. Where to start? Well, the open source world is unique in that plagiarism is encouraged :-) so the best place to start is probably with someone else's working example, and with lwIP it is no different. Several example applications exist and are maintained by the contributors on the lwIP source code repository site.

Sample projects include:

and more.