[Opensim-dev] A software to connect its own region and TP in from locally...

[Kyle Hamilton]

No real problem at all, except the idea that at that point you're
exposing details of the network-behind-the-NAT to the public internet,
which may provide information useful in an attack.

-Kyle H

On Tue, Jun 24, 2008 at 1:48 PM, Dalien Talbot <dalienta at gmail.com> wrote:
>
>
> On Fri, Jun 20, 2008 at 8:04 AM, Stefan Andersson <stefan at tribalmedia.se>
> wrote:
>>
>>
>> The issue you're seeing is known as the 'NAT bounce' or 'NAT
>> loopback' issue - your router only translates and/or forwards traffic
>> crossing the LAN-WAN border, which means that if you access your computer
>> with the _external_ IP from _within_ the LAN, the traffic isn't 'bounced'
>> back into the LAN, but is lost.
>>
>> Normally, you would solve this by simply address the computer with your
>> _internal_ IP from the inside (typically, you have host file settings or an
>> internal dns that serves internal ip's within the LAN)
>>
>> now, things are getting complicated with the Second Life viewer, as the
>> viewer demands regions be addressed with _IP_, not host name, so the viewer
>> never resolves anything, so host magic won't work.
>>
>> so, on login and teleports, when the grid tells the viewer where to start,
>> it would have to serve you your _internal_ IP - but your _external_ ip to
>> the rest of the world.
>>
>> Which gets complex.
>
> I think the vast majority of the cases (in the case the outbound connections
> are masked behind the same IP as the one used for the inbound port
> redirection) could be taken care of by a modification of the grid
> registration/teleport logic:
>
> 1) upon the registration, the region sends its IP "as seen locally"
>
> 2) the grid server takes that IP (denote as privateIP), as well as the IP it
> sees as source (denote it as publicIP) and keeps in the registration
> database.
>
> 3) upon the teleport request, the sending region informs the grid server
> about the IP of the client. The grid server compares this IP with publicIP -
> if they are the same, means the client is behind the home router - so the
> grid server returns the privateIP which the originating region uses to send
> the user to the target region. If the clientIP and publicIP are different -
> then the assumption is that the client and the server are on the different
> sides of the NAT - so the publicIP is used for the teleport.
>
> The (1) can be extended to also include N "known public client addresses"
> into the registration - so the condition for giving out the privateIP within
> the teleport packet is the equality of the client IP to any of those...
>
> any pitfalls in the above quick write up that I've missed ?
>
> /d
>
>
>
> _______________________________________________
> Opensim-dev mailing list
> Opensim-dev at lists.berlios.de
> https://lists.berlios.de/mailman/listinfo/opensim-dev
>
>