Hello, I've got a problem when using Twisted UDP-based app with IPv6. I know UDP IPv6 is not yet officially supported, I am using the unoffcial hack found somewhere on the net. ----------------UNOFFICIAL HACK---------------------- In twisted/internet/udp.py: (...) def __init__(self, port, proto, interface='', maxPacketSize=8192, reactor=None): """ Initialize with a numeric port to listen on. """ base.BasePort.__init__(self, reactor) self.port = port self.protocol = proto self.maxPacketSize = maxPacketSize self.interface = interface self.setLogStr() self._connectedAddr = None + if interface and abstract.isIPv6Address(interface): ### + self.addressFamily = socket.AF_INET6 ### (...) def doRead(self): """ Called when my socket is ready for reading. """ read = 0 while read < self.maxThroughput: try: data, addr = self.socket.recvfrom(self.maxPacketSize) except socket.error as se: no = se.args[0] if no in _sockErrReadIgnore: return if no in _sockErrReadRefuse: if self._connectedAddr: self.protocol.connectionRefused() return raise else: read += len(data) try: + addr = (addr[0], addr[1]) ### self.protocol.datagramReceived(data, addr) except: log.err() --------------END OF UNOFFICIAL HACK------------------------ I deploy my protocol like that: reactor.listenUDP(5683, myapp.MyProtocol(), interface="::") reactor.run() The problem is: 1. My server receives a request from remote client (with destination address being valid global IPv6 address) 2. The server sends a response, but uses different source address (which is also valid and assigned to local wlan0 interface). 3. Remote host drops the response (destination address of the request and source address of the response do not match). It is common for IPv6 interfaces to have multiple global IPv6 addresses - because of privacy reasons (both on Windows and Linux). My question is - can I read manually the destination address from the incoming request datagram, and set it as a source address manually in the outgoing response datagram? Best Regards Maciej Wasilak