[Opensim-dev] STUN for OpenSim?

[Infinity Linden]

STUN is used by a client to establish it's routable IP address. in
other words, the address a peer would have to connect to in order to
have a chance at crossing the NATting firewall.

DynDNS can help with this too, but is used to do name resolution.

they're effectively used for different scenarios. DynDNS and STUN can
both be used by systems which are given dynamic IP addresses from
their ISPs. depending on the type of fabric you want to use, either
might be useful. if you're talking about software that starts up,
registers it's IP address with a service, that's STUN. if you want to
publish a DNS name and have it route to your NATting firewall even if
you're on the wrong end of a dynamic IP address, thats DynDNS.

for what it's worth, STUN considered to address a subset of the
problem of maintaining stateful application layer sessions across a
NATted firewall. RFC5389 describes the problem in a little more
detail, along with more generic solutions. (
http://tools.ietf.org/html/rfc5389 )

RFC5389 describes a series of techniques for UDP messages to
successfully traverse a firewall that are not found in DynDNS.
Ultimately, a good read of 5389 and practical experience with your
firewall will do you a load of good.

-cheers
-meadhbh

On Tue, Jul 14, 2009 at 3:15 PM, Mojito Sorbet<mojitotech at gmail.com> wrote:
> If you are running OpenSim behind a NAT router, you are going to have to
> configure the routing in some way, regardless of whether STUN, or even
> TCP, is used.  That is because the connection is originating outside of
> the firewall, and the whole purpose of firewalls is to not let that
> happen, except in carefully prescribed circumstances.  Same thing
> applies to VOIP.
>
> The problem of people not being able to find your IP address has already
> been solved by services such as DynDNS.
>
> On Tue, 2009-07-14 at 07:57 +0200, Stefan Andersson wrote:
>> One of the main shortcomings of the linden-legacy model is that
>> OpenSim does not work well (as in simple and consistent)  from behind
>> NATs and several home routers.
>>
>>
>>
>> I was thinking, if something like STUN could help us overcome this?
>
>>
>
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