Open Aource application/protocol for internet applications

In near future I'll need to start working on a new project that consist of highly loaded TCP/IP servers and clients that communicate to that server. I know the basics of TCP/IP and can make the server and clients talk over the wire.

The problem is that I need to find some ways to protect server against other "clients" that can send bogus data and may crash the server. I'm looking for any ideas or recommendations for an application-level protocol that I can use for my application. Pretty sure there must be some kind of open-source MMORPG game that has already implemented such a protocol.

Any other ideas are very welcome.

P.S. I have chec开发者_开发百科ked already the WorldForge project.

Use authentication and write your server so that bogus data doesn't crash it. You can also utilize firewalls where appropriate.

Have a look at http://www.devmaster.net/ for game development. I've read many useful articles there.