UDP reverse proxying for OpenVPN isn't working using Nginx streams

Roman Arutyunyan arut at nginx.com
Wed Apr 26 14:56:23 UTC 2017

On Wed, Apr 26, 2017 at 09:42:22AM -0400, akb-nginx wrote:
> Thanks for your responce. I think I am out of luck then as far as proxying
> UDP openvpn is concerned. Any particular reason that Nginx took this
> approach instead of how very basic load balancers like "Pen" etc do it.
> I was able to proxy using simpler tools like pen and nc but a more loaded
> Nginx fails for the reasons you mentioned.

When operating in multi-worker mode, a UDP packet from a client may be received
by any worker.  Using SO_REUSEPORT can help with that on Linux, but not always.
Proxying becomes complicated if every packet of a UDP packet sequence is
received by a different worker.

Roman Arutyunyan

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