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Date: Tue, 7 May 2013 14:33:11 -0500
From: Eric van Gyzen <eric@vangyzen.net>
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To: Matthias Apitz <guru@unixarea.de>
Subject: Re: ppp(8) and inbound IP connections
References: <20130507181345.GA992@tiny.Sisis.de>
 <51894B52.2050903@rewt.org.uk> <20130507185623.GA1115@tiny.Sisis.de>
 <5189534D.4020605@vangyzen.net> <20130507192433.GA1304@tiny.Sisis.de>
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Cc: freebsd-net@freebsd.org, Joe Holden <lists@rewt.org.uk>
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On 05/07/2013 14:24, Matthias Apitz wrote:
> El día Tuesday, May 07, 2013 a las 02:17:33PM -0500, Eric van Gyzen escribió:
>
>>> Ofc, the provider must NAT somehow my local addr behind some routable
>>> valid IP addr, in our case 82.113.99.104; without this nothing would
>>> come back, even when the 1st SYN was from my side; the question is, why
>>> they do not manage the NAT table so any SYN to 82.113.99.104 is sent to
>>> my ppp link;
>>>
>>> or if they do send it, and my ppp config is wrong?
>> Most likely, multiple customers' local addresses are NATed to the same
>> routable address, so the router can't know which customer to chose for a
>> new incoming connection.  De-NATing of incoming packets for existing
>> sessions is done via per-connection state-tracking, which of course
>> doesn't exist for a new incoming connection.
> That is my understanding as well, but why they claim that they do
> support incoming connections?

Miscommunication, perhaps?

Eric