Re: [Openvpn-users] Re: Answering on the same interface where the request came from

[James Y. <ji...@yo...>]

On Thu, 24 Feb 2005, Jamie Lokier wrote:

> James Yonan wrote:
> > Listening on multiple sockets is also bad from a performance perspective 
> > unless you are using a modern polling API such as epoll on Linux 
> > 2.6.
> 
> That's only an issue if you have lots of interfaces.
> If you only have a few, poll() will be fine.
> 
> But, if you're going to have a little non-portability, it's much
> easier to use the IP_PKTINFO method of getting the incoming
> destination address and interface (IP_PKTINFO with recvmsg/sendmsg).
> 
> That has the advantage that you don't need to enumerate the
> interfaces, and you don't need to track interface changes: you can
> just use the received pktinfo struct for sending out the same
> interface, without interpreting it.

The NTP guys (another UDP server) had a bit of a low-grade burn over this:

http://bugzilla.ntp.org/show_bug.cgi?id=314

It seems the anti-IP_PKTINFO camp won out?

James