[ On Tuesday, June 15, 2004 at 09:18:59 (+0200), Giuliano Gavazzi wrote: ]
> Subject: RE: [Exim] AOL - SPF - and EXIM
>
> At 12:48 am -0500 2004/06/15, Edgar Lovecraft wrote:
> >
> > You do not need to control the in-addr.arpa space to have your ISP
> > setup a proper DNS PTR record for your Internet connected host(s). I
> > have never once had any ISP tell a client that they would not set a DNS
> > PTR record for them upon request, to point to a specifc DNS A record
> > that matches the IP address they want a PTR record for.
>
> you have been very lucky then.
Luck has nothing to do with it. It's all about matching your
requirements with service offerings and being willing to pay for what
you need.
Keep in mind that the whole point of the global public Internet is that
you don't have to be sitting directly in front of the computer(s) you
might use to provide services on the Internet. You could host your mail
server _anywhere_ and only use your local DSL connectivity to access
this wonderful global public Internet we have and thus use the
Internet's routing to access your remotely hosted mail server. Way too
many people seem to have this bogus notion that they have to host their
own servers on whatever connectivity they happen to be able to find at
their "home" location. This is not necessary and indeed it is often
very counter-productive too!
> > Well, that is, as long as the IP range that the client is on is not
> > with a 'non-reversable' IP range (i.e. Dynamic cable/dsl/adsl/dialup).
>
> oh well, the one above, incorrectly identified by Greg's clever
> routine as dynamic, is in one of the two (static) zones I use and on
> which I have no say DNS wise.
Do you mean this one? dsl-217-155-139-146.zen.co.uk
That one was caught because I had temporarily implemented a rather naive
regular expression for identifying potentially "dynamic" clients.
(i.e. there's nothing really clever about what I was doing :-)
I have done some tuning on that pattern in the past couple of days and
you may in fact be able to use that hostname again.
> Still, if I used the PTR for the
> server's HELO I would make a mistake, as the only name that really
> identifies that host is the FQDN that belongs to my domain, as I
> administer the server, not my ISP.
Huh? You are confused.
Your host's name _is_ "dsl-217-155-139-146.zen.co.uk".
You might not like that name, but it is the proper name of your host in
the context of the Public Internet, especially when it's acting as a
client (e.g. when the IP address for that hostname appears in the source
address field of a TCP connection).
The SMTP greeting command identifies the connecting client and must
match (i.e. resolve to) the IP address it connects from. There's no
defined relationship between that name and the mail domain(s) the
client-SMTP server might be speaking for.
Get over it. A hostname is just a hostname. That hostname is not used
to route your e-mail -- just to identify the/a host that might sometimes
send some of your e-mail.
As for who administers what, well it is in fact your ISP who administers
the address your server uses and thus it is their sole perogative to
decide what hostnames may legitimately be pointed at that address. If
they don't offer a service that also allows you to pay for the privilege
of pointing a hostname of your choice at the IP address they've assigned
to you then you're stuck with using the hostname they chose.
(I think zen.co.uk is rather stupid to assign such generic dynamic-like
hostnames to static address assignments, but I guess we can't expect
everyone to be perfect! :-)
--
Greg A. Woods
+1 416 218-0098 VE3TCP RoboHack <woods@???>
Planix, Inc. <woods@???> Secrets of the Weird <woods@???>
