[CLUE-Tech] NAT blocks P2P?

[Angelo Bertolli]

I think the idea is that this will hinder P2P when the chances of both 
sides being behind a NAT box increase.  Of course there is a way to do 
this: VPN.  Which is probably what will happen.  NAT is used to increase 
the namespace of IP addresses, and a VPN reduces them--but gives you the 
choice of which ones to include.  No, I don't think P2P will die because 
of this.  At home people will use port forwarding.  I think as long as a 
small subset of people are not behind a NAT box or are using port 
forwarding, everyone can be connected through built-in VPN in the P2P 
clients.

Jed S. Baer wrote:

>Hi Folks.
>
>Referring to this from the Politech mailing list:
>http://politechbot.com/pipermail/politech/2004-March/000524.html
>
>John Walker claims that increases in the use of NATted addressing by
>high-speed providers will eventually kill P2P connections on the internet.
>
>Since I'm no NAT guru, I wonder if this is really true? I understand that
>in order to establish a P2P connection, each box has to send out, or
>otherwise establish, its address, which isn't the same as the routing
>interface where NAT is happening. But I'd think there'd be a way for a NAT
>interface to somehow figure out that connection x is intended for a
>particular address/port on the "inside". IOW, the P2P request would be
>directed to the NAT interface, which ought to be able to figure out what
>do with it, based on recognizing the protocol, or which port the request
>comes in on.
>
>So, I'm just wondering.
>
>jed
>  
>