Re: blocking dialups
- Date: Tue, 13 Oct 1998 17:20:07 +0200
- Notice-requested-upon-delivery-to: unitfj@localhost
I feel pretty alone on this issue. What I was looking for was a
way to know when dialup ip's get allocated for other purposes.
Now, it's time for my last comments on this thread. Thanks.
On Tue, Oct 13, 1998 at 02:19:15PM +0200, Martin Lorensen wrote:
> On Tue, 13 Oct 1998, torben fjerdingstad wrote:
> > Can you mention just one reason for not relay through the ISP's
> > mail server (except for sending spam)?
> - Don't known the ISP's mailserver name (Roaming/IPass)
A good one. I don't know how that works or how to deal with it.
> - Running Linux server with sendmail.
Bad one. sendmail requires a fixed connection. If it is an isdn
dialup, it benefits by letting the ISP's mail server do the
hard work with slow deliveries, timeouts and retries.
If it's a fixed line, it's not a dialup.
> - Connects to diffrent ISP's.
I don't see the point. Roaming?
"Clive D.W. Feather" clive@localhost added:
> Here's two:
> (1) You are then reliant on the ISP's mail server; if that breaks in any
> way, you're dead in the water.
I would feel a lot more dead if I had to waste phone costs retrying
for days to do a delivery to santa claus, because his server is
Note. Our mail server has been 100% reliable since I installed
it on aug. 19. 1997.
> (2) A closed user group can authenticate mail to addresses based on the
> sender address; for example, I can email certain internal lists from my
> dialup, but not everyone else can.
I hope sender address means the ip address. Why would you want to
be able to deliver those mails to us?
> Oh, plus:
> (0) I buy access to the *Internet* from my ISP, not access to their
I can't imagine how two dialup customers at that ISP can mail each
other without a mail server at the ISP. Well, they could use pop3,
but we are talking about smtp here.
>> Sample output:
>> 220.127.116.11 => guest1.linx.org
> Which proves what ?
Nothing. It's just a sample output.
Since you ask I assume they are dialups. But they have not sent
me spam, so I have no reason to block them.
The directly sent spams I have seen came from large ISP's who have
whole class C networks allocated for dialups. I'm not so worried
about the rest of them.
Med venlig hilsen / Regards
Netdriftgruppen / Network Management Group
Tlf./Phone +45 35 87 89 41 Mail: UNI-C
Fax. +45 35 87 89 90 Bygning 304
E-mail: torben.fjerdingstad@localhost DK-2800 Lyngby