On Wed, Sep 07, 2005 at 09:08:25AM -0500, Seth Goodman wrote:
<long analysis (to which I _am_ sympathtic!) snipped>
The root problem that drives this is who owns the "last mile" of wiring to
the network premises. Unless you have your own T1 or other dedicated data
line from a company that you selected and brought in the line for you (at
your expense), small networks generally have to get connectivity via DSL
over local telephone lines or via cable modem from the local cable network.
There is often a local monopoly for both of these in a given geographic
area.
okay, I owe you an apology. I have heard this sort of thing before about
the situation with dsl in parts of the U.S., I never stopped to put it in
the context of PTR records and mail servers in particular.
Don't you have trouble with DUL lists ? or is there some form of segregation
that doesn't go as far getting you a PTR, but alleviates that pain ?
I agree that with substancial parts of the network unable to set a PTR it
undermines the (already limited) value of a PTR. I don't see that as a
reason for not regarding having a consistent PTR as desirable, instead I'm
inclined to regard the situation you describe as unfortunate breakage.
I can certainly see how any such widespread breakage would be a blocker
for using such information in a deterministic accept/reject way, but I've
never advocated that. All I'm saying is
PTR lookups are sometimes useful
MTAs do them on EHLO addresses
which I hope is non-controversial, followed by a naive
isn't it nice when the A record and the PTR match
I'm kinda wishing I hadn't originally bitten :)
Here in the UK we have a similar problem to the one you describe.
The last mile is owned by BT, even if your ISP is someone else.
That doesn't effect PTRs, but when BT screw up your line, there's
precious little choice. There's been a lot of regulation in the
UK market to break up the original state monopoly, and there's
more to come. Perhaps there's something in there that can help
wiht the situation you describe.
Regards,
Paddy
--
Perl 6 will give you the big knob. -- Larry Wall
-------
Sender Policy Framework: http://spf.pobox.com/
Archives at http://archives.listbox.com/spf-discuss/current/
To unsubscribe, change your address, or temporarily deactivate your
subscription,
please go to
http://v2.listbox.com/member/?listname=spf-discuss(_at_)v2(_dot_)listbox(_dot_)com