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Re: argh ... I wish people would RTFRFC

2004-09-08 18:42:03
mholm(_at_)medrad(_dot_)com wrote:

An A record assigns an IP address to a domain name. I believe the
erroneous "a:1.2.3.4" representation happens because people mentally
interpret the RHS of what comes after the ":" as that which is
assigned to the A record: an IP address.

The wizard that Microsoft sponsors:
http://www.anti-spamtools.org/SenderIDEmailPolicyTool/Default.aspx
asks the user to do exactly what you say is incorrect.

Does it?

<Direct quote from the page>

Enter any additional IP addresses (or ranges of addresses) you wish
to add to
your SPF Record (one address or address range per line).
Examples:
1.2.3.4
1.2.3.4/24

<End quote>

That quote is preceeded by this text:

   "At present, the domain's A records contain the following addresses:"

It does NOT say: "A mechanisms" (which is correct). And when I enter an IP address there, I get an "IPv4" mechanism, not "a" (which is correct):

   v=spf2.0/pra ... ip4:1.2.3.4/24

Actually, lol, I get an "ip4" mechanism. :) But that aside,

Furthermore, the correct way of using a, all by itself, doesn't work
in this wizard, even though a check box to designate it is present.
The incorrect way is cheerfully passed through to the end result,
e.g. a:123.123.123.123

How did this occur? When I fill in the spot where it says:

"Enter any additional domain names you wish to add to your SPF Record (one domain name per line),"

I (correctly) get:

   v=spf2.0/pra ... a:teshost.com

Seems pretty much in order to me (though I could do without the "v=spf2.0/pra"; but, hey, it is their Sender-ID wizard).

The Microsoft wizard, however, does (erroneously) NOT support:

   a:colo.example.com/28

Which it SHOULD. Instead, you get an error:

"* One or more domain names have invalid syntax."

I don' think so. :) See:

http://spf.pobox.com/spf-draft-200406.txt

The wizard at http://spftools.net/create.php  says:

<Direct quote from the page>
If there is another named host or subnet that can send mail from this
domain, enter it here, with the CIDR block size if appropriate:
(If you need to specify a host/subnet by IP address, please use an
IP4 record)
<End quote>

Now, if you know the meaning, this may seem clear, but when I read it
the first time, not really understanding, I read it as an invitation to do
exactly what you are complaining about.

That quoted text appears in the "Named Servers (A)" section. To my knowledge of the current draft, I do indeed not believe that you can "specify a host/subnet by IP address" is correct here. Not with an "a" mechanism, that is.

Cheers,

- Mark

       System Administrator Asarian-host.org

---
"If you were supposed to understand it,
we wouldn't call it code." - FedEx