During 2-player testing the other person was sometimes disconnected, server log:
INFO Invalid DMP mesage from :49755
INFO Client x disconnected, sent CONNECTION_END to endpoint :49755

It happened 9 times in about 45 minutes. I was hosting the server and connecting locally. I'm not aware of any connection issues, stable ping around 50-70ms to the other player. Each time the other player was able to reconnect easily.

Development build as listed on the dmp build site:
Tag: d25ca7de9bb33c7bca66d81d2688c2aea6636e11
Build date: Sun May 18 05:50:35 UTC 2014

Invalid DMP messages are messages that don't follow the DMP format of (4-byte int type)(4-byte int length)(payload bytes), or they send a message type that is out of range.

This should only ever happen if a non-DMP program connects to a DMP server.

I did make the mistake of forgetting to bump PROTOCOL_VERSION during 5bf31af to 5dd5a32 - If you were running 5bf31a... that could cause the problem.

Also, d25ca7d doesn't exist in my repo, which is slightly interesting...

Thank you for the explanation, let's assume it's related to the missed protocol version bump and close for now :). I was also wondering about the tag... strange.

For reference - My build script was doing a git pull instead of git fetch/reset, and it was creating merge commits :P

It's fixed now.

Also, I've improved disconnection in 4aa7cf1, so PROTOCOL_VERSION 6+ disconnections will be clear.