Re: [tlug] Re: 'Postfix' as SMTP AUTH Client

[Jonathan Q <jq@example.com>]

On Thu, Jun 05, 2003 at 10:51:16PM +0900, Shimpei Yamashita wrote:

>That's because--assuming you're using GOL's Flet's-somethingortheother
>service--you are, in fact, NOT directly connected to GOL's own network.

Quite right.  Flet's belongs to NTT, and any ISP offering Flet's
service is outsourcing it through NTT.  Your packets go from your 
computer through the NTT Flet's network and over a leased line
(usually; unless the ISP has a co-lo with NTT, in which case it
could be ethernet) and then to/from the Internet through the ISP's
network.

This is a good arrangement for ISPs, since it gets them DSL
infrastructure that few - even the big ones - could afford on
their own, but it does have a downside.  When you outsource DSL,
authentication and the ability to (immediately) terminate a connection
in cases (fortunately, these are still relatively rare in Japan) such
as an active spam run going on rest not with the ISP, but with the
infrastructure owner. 

If you notice a spam run going on (which often can be noticed if you
don't allow port 25 connections outside of your own network, since
the postmaster will start seeing lots of spam bounces show up), you
can shut out that connection from your SMTP servers, but there's
you can directly do to terminate the connection.  You have to 
do it manually by contacting the outsourcing provider, which makes
getting an abuser off of your network much harder and more
time-consuming than if it is on your dial-up network, where you own
the infrastructure yourself and can just remove the spammer from 
your RADIUS database and then terminate the connection with a smile.

And yes, it does feel good to terminate a spammer's connection.
It feels really good :-)

Jonathan

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