Thanks all. I was going to write everything below, then finally tracked it down.
A specific library was keeping the port open. I'm tracking down how/why right now. The worry on this, FYI, was that there is a critical vulnerability in glibc from a few months ago where a server could be compromised via UDP traffic. One of my servers was compromised last week, and I think the vector was in-part exploiting that bug (it was also exploited by redis, but redis was secured, so somehow it got loosened). On Apr 20, 2016, at 9:22 AM, Jean-Paul Calderone wrote: > What do the logs for the app say? Twisted logs a message when it binds a UDP > port. Nothing. I don't think Twisted itself is doing this, I think it's just happening when other code is running in twisted. > You could also try sending some traffic to the port and see what happens. :) > Maybe you'll get something back that identifies it or maybe you'll provoke > some more logging code somewhere. That was my first attempt! It just closed the connection no matter what I sent. I also made about 20 test cases. > Or, another though, you could put a breakpoint on listenUDP (or socket.bind > or something) and then run the process under pdb and look at the stack trace. Aggressive use of pdb.set_trace() on some modified code finally let me find the issue. _______________________________________________ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
