[Twisted-Python] txThings - simple library for CoAP protocol

[Phil Mayers]

On 23/11/13 12:03, Maciej Wasilak wrote:

> 3. There is a problem with txThings IPv6 server, because in most
> operating systems source address of datagram is determined in round
> robin fashion. It may cause the source address of the response to be
> different than destination address of the request.

This is in general a bit of a pain with UDP apps.

In Twisted, the easiest solution is to specifically bind the UDP sockets 
to the IP address(es) on the host, and always reply on the same 
protocol/transport you received on.

You may find the "netifaces" package helpful for getting a list of IPs 
in a cross-platform manner.

In theory you can avoid doing this if you have sendmsg/recvmsg support, 
but Twisted doesn't have this (yet).