Relaying some UDP traffic through tinc?

[Alex Corcoles]

Hi,

On Fri, 2018-04-13 at 18:17 +0100, Etienne Dechamps wrote:
> I can confirm that Steam In-Home Streaming does work properly over
> tinc, for having tried it myself, as long as tinc is configured to
> route the broadcasts properly, as Guus described.

Hmmm, tinc 1.11 is not in Debian stable so I guess this will be a bit
of a PITA to set up.

>  Note that it would be easier to set up tinc nodes on your Windows
> desktop and Linux laptops, to avoid the additional complication of
> having to relay broadcast packets between your local networks and the
> tinc network. This is what I do in my setup.

But both systems will be behind NAT routers. I could forward a port to
the Windows desktop and use that, but it seems a bit longwinded. Or I
could do the tinc-over-tinc, I guess, but I'm a bit concerned about
latency.

> That said, it strikes me as a bit odd that Steam is sending broadcast
> to a .127 address. That would indicate that your local network is
> configured as /25, which could be a valid configuration but is a bit
> unusual. Are you sure your subnets are configured correctly?

Well, actually I do use a /25 deliberately (I use a /25 for the local
network and another /25 for ocserv), but reviewing it I noted that my
DHCP range was not correctly configured, thanks!

Maybe I can tell my DHCP server to send 255.255.255.255 as the
broadcast address... I must admit I'm setting up a too-complex network
for my limited network knowledge (though I hope I'll learn a bit doing
so).

Cheers,

Álex

> On 13 April 2018 at 07:10, Guus Sliepen <guus at tinc-vpn.org> wrote:
> > On Thu, Apr 12, 2018 at 11:57:27PM +0200, Alex Corcoles wrote:
> > 
> > > I've got a four site site-to-site tinc mesh working nicely. I
> > have the
> > > following systems at two of those sites:
> > > 
> > > 10.a.a.2: Linux box running tinc and DHCP/DNS for site A
> > > 10.a.a.dhcp: Windows desktop with a GPU
> > > 10.b.b.2: Linux box running tinc and DHCP/DNS for site B
> > > 10.b.b.dhcp: Linux laptop
> > > 
> > > I'd like to use Steam In-Home Streaming to game in the laptop
> > streaming
> > > from the desktop. The Steam protocol is not well documented, but
> > it
> > > seems to rely on UDP broadcasts to x.x.x.127 UDP port 27036 to
> > discover
> > > remote nodes.
> > 
> > Tinc itself supports UDP broadcast packets. However, in router
> > mode, it
> > will only treat 255.255.255.255/32 and 224.0.0.0/4 as broadcast
> > address
> > ranges. If you are using tinc 1.1pre11 or later, you can add the
> > following to your tinc.conf files:
> > 
> > BroadcastSubnet = x.x.x.127
> > 

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